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Reference Studies

Category: Educational Articles

There are numerous studies that demonstrate the safety and efficacy of enzymes and probiotics for use as dietary supplements.  We’ve listed summaries and links to just a few of the available studies.


Some features of intestinal absorption of intact fibrinolytic enzyme III-1 from Lumbricus rubellus
A 2001 study in China investigated the body’s response to certain extracts of an earthworm, Lumbricus rubellus. Researchers found that these extracts contained six different fibrinolytic isoenzymes (EFEs). Two of the six isomers, called EFE-III-1 and III-2, demonstrated fibrinolysis, which is a process that helps dissolve blood clots.

Changes in coagulation and tissue plasminogen activator after the treatment of cerebral infarction with lumbrokinase
This case study, completed back in 2000, investigated the effect of the enzyme “lumbrokinase” on the anticoagulation and fibrinolysis (the breaking down of blood clots) in treating certain types of strokes. Lumbrokinase is an enzyme sourced from Lumbricus rubellus, a species of earthworm.

A novel fibrinolytic enzyme extracted from the earthworm, Lumbricus rubellus
For thousands of years, earthworms have been used in China and the Far East as a drug material for the treatment of various diseases. This was a detailed pharmacological report from 1991 on a newly-discovered fibrinolytic enzyme (its ability to break down blood clots) sourced from a species of earthworm. The findings here show the biochemical characteristics and biological nature of this enzyme.

Intestinal Absorption of Fibrinolytic and Proteolytic Lumbrokinase Extracted from Earthworm, Eisenia andrei
This 2010 report investigated the body’s intestinal response to enzymes (called lumbrokinase) taken from the extracts of the Eisenia andrei earthworm. The results support the notion that lumbrokinase can be absorbed from the intestines into the blood by oral administration.

Comparative evaluation of alpha-galactosidase A infusions for treatment of Fabry disease
With the demonstrated success of enzyme therapy for genetic lysosomal storage diseases like Gaucher disease, this 2003 study developed a trial comparing the same enzyme infusions in the treatment of Fabry disease, another genetic metabolic disease. Results showed improvements in the health of Fabry disease patients with enzyme therapy, but the report emphasized the need for additional long-term data.

Enzyme replacement therapy in Fabry disease- a randomized controlled trial
This 2001 study evaluated the safety and efficacy of enzyme replacement therapy for patients with Fabry disease, a metabolic disorder with no specific treatment options that is caused by a deficiency of a certain lysosomal enzyme. Most patients with this disease experience debilitating neuropathic pain and often premature death. The findings concluded that intravenous infusions were safe and have widespread therapeutic efficacy for Fabry disease patients.

Evidence that pancreatic proteases enhance vitamin B12 absorption by acting on curde preparations of hog gastric intrinsic factor and human gastric juice
A 1977 study examined the malabsorption of B12 vitamins for patients with pancreatic deficiencies, such as exocrine pancreatic insufficiency (EPI), a disorder that interferes with the digestion of food. This report outlines the findings of using pancreatic enzymes on patients with this deficiency for the enhancement of vitamin B12 absorption.

Mixture of trypsin, chymotrypsin and papain reduces formation of metastases and extends survival time of C57B16 mice with syngeneic melanoma B16
Scientists conducted a study in 2001 about the effects of proteolytic enzymes – or the various enzymes that help with the breakdown of protein – on mice with metastatic melanoma. The results showed a decrease in the formation of secondary malignant growths and an increase in extended survival time.

Oral therapy with proteolytic enzymes decreases excessive TGF-beta levels in human blood
A 2001 study showed the effectiveness of using oral proteolytic enzymes (enzymes that help break down proteins) for treating illnesses like cancer that are known to be accompanied by excessive TGF-β1 production. TGF-β1 is a protein that controls cell growth and cell differentiation. It has been demonstrated that these oral enzymes reduce levels of TGF-β1 in human serum.

Prevention of murine EAE by oral hydrolytic enzyme treatment
This study on enzyme treatment, completed in 1999, showed the effects of Phlogenzym (a combination of enzymes for breaking down proteins) as a treatment for autoimmune diseases. This was a continuation of ongoing studies of Phlogenzym for multiple sclerosis (MS), type 1 diabetes and rheumatoid arthritis. This particular trial tested mice that had been injected with experimental allergic encephalomyelitis (EAE), which is an animal model of MS.

Safety and efficacy of recombinant human alpha-galactosidase A replacement therapy in Fabry’s disease
A randomized, placebo-controlled, double-blind study of 58 patients conducted in 2001 showed the safety and effectiveness of using a specific type of enzyme, called recombinant a-galactosidase A, as a treatment for individuals with Fabry’s disease. This is a genetic metabolic disease that often leads to premature death.

Safety evaluation of a lactase enzyme preparation derived from Kluyveromyces lactis
In 2000, a preparation of lactase enzymes underwent a series of toxicological tests to document the safety of its use as a processing aid in the dairy industry. Pretreatment of milk with this preparation gives access to individuals that suffer from lactose intolerance; they can then benefit from the nutritional quality of milk and milk-derived products. No safety concerns were identified in these studies.

Safety evaluation of a lipase enzyme preparation, expressed in Pichia pastoris, intended for use in the degumming of edible vegetable oil
A study from 2006 examined the safety of a certain type of lipase (an enzyme that helps with the breakdown of fats) intended for use in the refining process of edible vegetable oil. The lipase was tested for its effects on genotoxicity, as well as in acute, inhalation, and subchronic toxicity studies. The results of the studies attested to the safety of the use of this lipase.

Safety evaluation of a lipase expressed in Aspergillus oryzae
A program of studies conducted in 1996 established the safety of a particular lipase to be used in the detergent industry and as a processing aid in the baking industry. Laboratory animal studies were used to assess general and inhalation toxicity, skin sensitization, and skin and eye irritation. The study concluded that the lipase appeared safe for consumers, had low environmental impact, and required no special occupational health precautions.

Safety evaluation of a phytase, expressed in Schizosaccharomyces pombe, intended for use in animal feed
In 2003, a toxicity study tested BD006 phytase, an enzyme that is used in animal feed and helps provide essential nutrients for growing animals. The study concluded that this type of enzyme was safe for use in animal feed applications.

Safety evaluation of a xylanase expressed in Bacillus subtilis
A safety evaluation was conducted in 2001 of a xylanase (an enzyme commonly found in microbes and fungi) and its use as a processing aid in the baking industry. To assess oral toxicity, scientists conducted rat feeding studies. The findings indicated that xylanase can be considered a safe processing aid for use in milling and baking.

Safety evaluation of amino peptidase enzyme preparation derived from Aspergillus niger
In 1988, scientists conducted a study on an aminopeptidase enzyme preparation to test for toxicity and to document the safety of its use as a processing aid in food. The enzyme preparation was examined for subacute and subchronic oral toxicity, and its potential for mutation. No safety concerns were identified in these studies.

Safety evaluation of an alpha-amylase enzyme preparation derived from the archaeal order Thermococcales as expressed in Pseudomonas fluorescens biovar I
This case study from 2002 presented an assessment of the safety of a specific protein enzyme (a-amylase) used in the breakdown of starches, with applications in food processing, including the production of high-fructose corn syrups and nutritive sweeteners. Based on these data, this enzyme preparation was considered safe for use in food production.

Safety evaluation of beta-glucanase derived from Trichoderma reesei- summary of toxicological data
In a 1995 case study, an enzyme called Barlican commonly used as a feed additive was subjected to a series of toxicological tests to ensure its safety. The enzyme product was examined for general oral toxicity, inhalation toxicity, irritation to eye and skin, skin sensitization and its potential for mutation. A strong skin-sensitizing potential of the enzyme was detected, but no other evidence of toxicity was found.

Safety evaluation of lipase derived from Rhizopus oryzae- summary of toxicological data
This case study from 1997 reported on a series of toxicological tests that were conducted on a lipase enzyme (an enzyme that helps with the breakdown of fats) to ensure the safety of its use as a food additive. The enzyme product was examined for acute, subacute and subchronic oral toxicity, and potential for mutation. No evidence of oral toxicity or mutagenic potential was found.

Safety evaluation of lipase G from Penicillium camembertii
In 1994, scientists tested Lipase G, an enzyme produced by a species of fungus called Penicillium camemberti, to ensure its safety when used in food processing. The toxicological studies on the enzyme included a 90-day study with rats, a mutagenicity study using bacteria, and a pathogenicity study using mice. Results showed that the production and use of this enzyme is safe for both the enzyme production worker and the consumer.

Safety evaluation of lipase produced from Candida rugosa- summary of toxicological data
This 13-week dietary toxicity study was conducted in 2000 on lipase AY, an enzyme used for the breakdown of oils and fatty acids in order to produce flavors. Laboratory rats were given the enzyme in their food at varied concentrations. No adverse treatment-related effects were observed.

Safety evaluation of lipase produced from Rhizopus oryzae- summary of toxicological data
This 2003 study tested the toxicity of Lipase D, an enzyme used to break down fatty acids. Sprague–Dawley rats received the enzyme at varied levels. At a certain dose, scientists observed an increase in urine acidity, but otherwise there were no effects on electrolyte balance, kidney weight, or histology of the kidney. These studies concluded that Lipase D was safe when used as described in the processing of dietary fatty acids.

Systemic enzyme therapy in oncology- effect and mode of action
This study, published in 2000, provided an overview of trials that were being conducted for the use of pancreatic enzyme and proteolytic enzyme (enzymes that help break down proteins) therapy in oncology. The beneficial effect of this type of enzyme therapy seems to be based on its anti-inflammatory potential. However, the precise mechanism of action of this enzyme therapy remains unsolved.

Transport of proteolytic enzymes across Caco-2 cell monolayers
In a study from 1998, scientists sought to identify the ways by which proteolytic enzymes (enzymes that help break down proteins) can be absorbed from the intestinal tract after oral administration to humans. During the study, these enzymes were found to have dramatic effects on the permeability of intestinal tissues, which facilitated the transport of compounds that were normally non-absorbable.

Trypsin, elastase, plasmin and MMP-9 activity in the serum during the human ageing process
The aim of this study, completed in 1998, was to test whether the ageing process in humans had any influence on the activity of proteolytic enzymes (enzymes that help break down proteins). In humans, ageing is a physiological process where cells, tissues and organs go through gradual structural changes over many years. The results indeed confirmed that the activity of individual proteolytic enzymes in a human’s serum changes with age.


Proteinase activity and stability of natural bromelain preparations
Bromelain is a complex mixture of enzymes that breaks down proteins (called proteinases), which typically derive from pineapple stems. Beneficial therapeutic effects of bromelain have been suggested or proven in several human and animal studies of inflammation, including arthritis and inflammatory bowel disease (IBD). This particular study from 2005 was a controlled trial to further test the effectiveness of bromelain. Conclusions of the test indicated that further studies need to be performed to establish its efficacy as an anti-inflammatory drug. However, the article concluded that these studies will facilitate the initiation of future clinical trials on this therapy.

Bromelain treatment decreases neutrophil migration to sites of inflammation
This study from 2008 took a closer look at bromelain, a mixture of enzymes that breaks down proteins (called proteinases), to figure out what makes these enzymes have anti-inflammatory properties. During these tests, scientists discovered that bromelain can effectively decrease the migration of white blood cells (called neutrophils) to areas of the body with acute inflammation.

Bromelain inhibits lipopolysaccharide-induced cytrokine production in human THP-1 monocytes via the removal of CD14
Though bromelain, a mixture of enzymes that breaks down proteins (called proteinases), has been reported to have anti-inflammatory and immunomodulatory effects, the anti-inflammatory mechanism of bromelain is unclear. Therefore, scientists from this 2008 study investigated the effect of bromelain on cytokine production from certain types of human cells. Cytokines are molecules that facilitate the communication between cells in immune responses.

Bromelain modulates T cell and B cell immune responses in vitro and in vivo
This study from 2001 was initiated because the types of immune cells affected by bromelain were unconfirmed. Bromelain is a mixture of enzymes that breaks down proteins (called proteinases). The resulting findings provided important insights into the immunomodulatory activity of bromelain (meaning, bromelain’s ability to regulate immune functions) and are important implications for the use of certain types of enzymes as additives in vaccines or other agents.

In vitro study on the immunological effect of bromelain and trypsin on mononuclear cells from humans
Proteolytic enzymes (enzymes that help break down proteins), such as bromelain and trypsin, have been used as a therapeutic approach in the treatment of chronic inflammatory, malignant and autoimmune diseases. In this study from 2005, scientists analyzed the influence of bromelain and trypsin on the cytokine production of specific types of cells from patients with encephalomyelitis disseminata (ED) as well as from healthy individuals participating in the study. Cytokines are molecules that facilitate the communication between cells in immune responses.

Bromelain, from pineapple stems, proteolytically blocks activation of extracellular regulated kinase-2 in T cells
This study from 1999 showed that the enzymes that help to break down proteins, such as bromelain, may also block cell signaling. This article discusses how bromelain works to inhibit cell signaling and cytokine production in immune helper cells (specifically, Th0 cells). Cytokines are molecules that facilitate the communication between cells in immune responses.

Oral administration of protease inhibits enterotoxigenic Escherichia coli receptor activity in piglet small intestine
A study from 1995 aimed to examine the effect of bromelain (a complex mixture of enzymes that help to break down proteins) on E. coli cell receptor activity in the small intestines of pigs. Bromelain was administered orally to piglets. It was concluded that administration of bromelain can inhibit E. coli cell receptor activity and may therefore be useful for prevention of symptoms brought on by E. coli.

The influence of bromelain on platelet count and platelet activity in vitro
The aim of this study from 2005 was to investigate the influence of bromelain (a complex mixture of enzymes that help to break down proteins) on platelet count, platelet aggregation and platelet activity in living humans. Results indicated that there may be potential for future use of bromelain as a substance for platelet inhibition.

In vivo antitumoral activity of stem pineapple (Ananas comosus) bromelain
This 2007 study of bromelain (a complex mixture of enzymes that help to break down proteins) was conducted to identify the antitumoral qualities (inhibiting the development of tumors) of the pineapple stem from which bromelain is sourced. Scientists did this by isolating bromelain to probe its medicinal effects. The main medicinal use of bromelain is recognized as digestive, in vaccine formulation, in fighting tumors and in skin debridement for the treatment of burns.

Improvement in protein utilization in nursing-home patients on tube feeding supplemented with an enzyme product derived from Aspergillus niger and bromelain
In 2001, a study was conducted on elderly nursing home patients that were receiving nutrients through a feeding tube. This was to test whether adding an enzyme-based digestive aid called AbsorbAid could be beneficial for the nutritional status of elderly patients, particularly those suffering from diarrhea. Malabsorption of nutrients (which occurs when the patient has chronic diarrhea) is common in the elderly and can compromise nutritional status, disease resistance, overall health and longevity.

Bromelain treatment decreases secretion of pro-inflammatory cytokines and chemokines by colon biopsies in vitro
To assess the effectiveness of using bromelain (a complex mixture of enzymes that help to break down proteins) as a treatment for inflammatory bowel disease (IBD), a study was conducted in 2007 on the biopsies of different patients that were considered healthy, those that had ulcerative colitis (UC) and those with Crohn’s disease (CD). These biopsies were given bromelain and then cultured. Results indicated that bromelain may be a novel therapy for IBD.

Use of Bromelain for Mild Ulcerative Colitis
This article from 2000 presents two separate case studies of patients using supplementation. The first case study reported on two different patients with types of ulcerative colitis (UC) that used bromelain supplementation (a complex mixture of enzymes that help to break down proteins) and achieved remission. The second study reported on a case of possible acute pancreatitis associated with taking celecoxib (a nonsteroidal, anti-inflammatory drug).

A randomized, double-blind, placebo-controlled study of oral hydrolytic enzymes in relapsing multiple sclerosis
A double-blind, placebo-controlled study was conducted in 2005 to assess the safety and efficacy of orally-administered hydrolytic enzymes (HE) in patients with relapsing multiple sclerosis (MS). Scientists initiated the study based on experimental data and claims that these enzymes, which include bromelain, trypsin and rutosid, could reduce the relapse rate and potentially halt progression of MS.

Bromelain in the early phase of healing in acute crush Achilles tendon injury
This 2010 study investigated the effects of bromelain (a complex mixture of enzymes that help to break down proteins) on the increased reproduction of tendon cells in the early stages of healing in an injury to the Achilles tendon. The study was conducted on Sprague Dawley rats. Bromelain has been proposed as a treatment for reducing pain and swelling following acute muscle injuries but prior to this case, studies were yet to be done on its effect on tendon healing.

Protease Supplementation Improves Muscle Function after Eccentric Exercise
This study from 2009 was conducted based on a hypothesis that taking protease (enzymes that break down proteins) orally would reduce muscle damage and improve skeletal muscle function after strenuous exercise. The results in this study indicated that 21 days of dietary supplementation with orally-ingested proteases significantly improved muscle function after an eccentrically damaging exercise. These results were in agreement with previous findings.

Bromelain reduces mild acute knee pain and improves well-being in a dose-dependent fashion in an open study of otherwise healthy adults
This study conducted in 2002 investigated the effects of bromelain (a complex mixture of enzymes that help to break down proteins) on mild acute knee pain of less than three months duration in otherwise healthy adults. Preliminary clinical evidence supported the contention that the anti-inflammatory and pain relieving properties of bromelain help to reduce symptoms of osteo- and rheumatoid arthritis. However, prior to this study, there had been no controlled studies of its effects on joint health in healthy subjects that lacked this diagnosis.

Therapeutic Use, efficiency and safety of the proteolytic pineapple enzyme bromelain-POS in children with acute sinusitis in Germany
The therapeutic efficiency and safety of bromelain (a complex mixture of enzymes that help to break down proteins) was evaluated in this 2004 trial with children under the age of 11 that had been diagnosed with acute sinusitis. This trial documented that bromelain is widely used for this type of treatment in Germany and that the use of these types of enzymes can benefit such patients.

Proteolytic activity and immunogenicity of oral bromelain within the gastrointestinal tract of mice
Based on evidence from previous studies suggesting that bromelain has anti-inflammatory benefits when given to living organisms, this 2004 study was conducted in order to determine whether ingested bromelain is able to be broken down within the gastrointestinal tract of living mice. Bromelain is a mixture of enzymes found in pineapples stems that digest protein.


Anti hypertensive substances in fermented soybean natto
This 1993 study looked at the effectiveness of natto (a traditional Japanese fermented food) in suppressing the development of hypertension. The relationship between natto and blood pressure had been noted in studies from the 1970s, which reported the suppression of blood pressure of rats when fed natto. This study further detected natto’s ability to treat hypertension, and suggested that its effect is due to the interception of the renin-angiotensin system (a physiological system in the body that regulates blood pressure).

Enhancement of the Fibrinolytic Activity in Plasma by Oral Administration of Nattokinase
This study from 1990 investigated the fibrinolytic qualities (meaning, capable of dissolving blood clots) of a potent enzyme called nattokinase (NK) that is found in natto, a traditional Japanese fermented food. The trial demonstrated that oral ingestion of NK can enhance fibrinolytic activity in the blood for long periods of time. Thus, NK represents a possible drug for use in the treatment and the prevention of blood clots and embolism (a sudden blockage of an artery).

Fibrinolytic enzymes in Asian traditional fermented foods
This 2004 study examined the benefits of fibrinolytic enzymes (meaning, capable of dissolving blood clots) that are found in a variety of traditional Asian foods. In this study, enzymes were purified from these foods, and their physicochemical properties were characterized. Fermented shrimp paste, a popular Asian seasoning, was shown to have strong fibrinolytic activity. These novel fibrinolytic enzymes are useful for thrombolytic therapy (a therapy used in medicine to dissolve blood clots).

Intake of Natto is associated with reduced bone loss in postmenopausal women
Natto, or Japanese fermented soybeans which contain a large amount of vitamin K2, may help prevent the development of osteoporosis. In this 2005 study, scientists assessed the possibility of an association between regular natto intake and bone mineral density (BMD), as well as BMD change over time in healthy Japanese women who participated in the study.

Nattokinase decreases plasma levels of fibrinogen, factor VII, and factor VIII in human subjects
In this study from 2009, scientists hypothesized that a potent enzyme called nattokinase (NK) could reduce certain factors of blood clotting and lipids that are associated with an increased risk for cardiovascular disease (CVD). Thus, an open-label, self-controlled clinical trial was conducted on subjects of the following groups: healthy volunteers, patients with cardiovascular risk factors and patients undergoing dialysis. The findings reported that oral administration of NK could be considered a CVD nutraceutical (meaning, it has health-improving qualities and medicinal benefit).

Super Oxide Dismutase (SOD)

Superoxide Radical and Superoxide Dismutases
This article from 1995 took an in depth look at the biology of oxygen radicals. These statements were offered, according to the scientists, as a rationalization for how slowly the scientific community has gained an understanding of the basis of O2 toxicity and the nature of the counterbalancing defenses. This study built upon ongoing studies that have been dedicated to learning about the biology of O2 and of the SODs that remove it. (SOD stands for superoxide dismutase, which is a powerful enzyme the body uses as a defense against oxygen toxicity.)

Influence of age on activities of antioxidant enzymes and lipid peroxidation products in erythrocytes and neutrophils of down syndrome patients
In 2001, scientists studied a group of individuals with Down syndrome (DS) in order to monitor the differences, depending on age, in the way their bodies metabolized antioxidant enzymes and lipids. DS is known to be accompanied by increased activity of SODs and, at the same time, immune system disorders. (SOD stands for superoxide dismutase, which is a powerful enzyme the body uses as a defense against oxygen toxicity.)

Intraoral manganese superoxide dismutase-plasmid.liposome (MnSOD-PL) radioprotective gene therapy decreases ionizing irradiation-induced murine mucosal cell cycling and apoptosis
In 2004, a group of scientists conducted a study on mice that were receiving radiation within their head and neck regions. Previous studies indicated that with oral administration of a specific type of enzymes, the animals had a significant decrease in oral ulceration and weight loss, and had an increase in survival rates. This particular study demonstrated the way these enzymes protect against radiation and also explored the possibility of using Amifostine (a protective drug against the effects of chemotherapy and radiation) alongside these enzymes.

Cu/Zn superoxide dismutase modulates phenotypic changes in cultured fibroblasts from human skin with chronic radiotherapy damage
Superficial radiation-induced fibrosis (RIF), an effect of therapeutic or accidental high-dose radiation (used in oncology), is well known in clinical practice. It is characterized by local inflammation and swelling. (Fibrosis indicates thickening and scarring of connective tissues.) This study from 2001 examined if it was possible to reduce chronic radiotherapy damages. To do this, scientists took cultures from normal or RIF skin and treated with various doses of LipSOD (a particular type of enzymes).

Topical superoxide dismutase reduces post-irradiation breast cancer fibrosis
Fibrosis following radiation for breast cancer is a frequent undesired effect with objective (aesthetic) and subjective (pain) consequences. (Fibrosis indicates thickening and scarring of connective tissues.) In this 2003 study, 44 patients with clinical radiofibrosis following treatment of breast cancer were evaluated after being given an anti-fibrotic enzyme called copper zinc superoxide dismutase. Treatment was well tolerated, except for one case of local allergic reaction.

Supplementation with gliadin-combined plant superoxide dismutase extract promotes antioxidant defences and protects against oxidative stress
Whether it is more beneficial to get antioxidant enzymes through nutrition or by taking supplements has long been a matter of controversy. However, this 2004 study found that the supplementation of Glisodin® (a patented supplement that promotes the body’s natural antioxidant system) could be very effective. By taking this supplement orally, scientists discovered that it helped to delay the degradation of antioxidant enzymes during the gastrointestinal digestive process, and also promoted cellular defenses by strengthening the antioxidant status.

Effect of encapsulation on the anti-inflammatory properties of superoxide dismutase after oral administration
This 1995 study examined the anti-inflammatory properties of a specific type of enzyme called superoxide dismutase. Scientists discovered that when encapsulated in liposomes (which are liquid filled spheres that can be filled with nutrients and then used to deliver nutrients into the body), this enzyme has higher anti-inflammatory effects than when the enzyme is free.

Anti-inflammatory activity of various superoxide dismutases on polyarthritis in the Lewis rat
The anti-inflammatory activities of enzymes called superoxide dismutases, or SODs, were compared in an early study on rats. In order to further this comparison and to discover how SODs accomplish an anti-inflammatory response, this study was conducted in 1989 to evaluate the activity of rat, bovine and human enzymes on a model of chronic inflammation.

Superoxide dismutase ameliorates TNBS-induced colitis by reducing oxidative stress, adhesion molecule expression, and leukocyte recruitment into the inflamed intestine
Oxidant stress has been implicated in the development of inflammatory bowel disease (IBD). (Oxidant stress is a disturbance in the balance between the body’s production of free radicals and its antioxidant defenses.) Antioxidant enzymes, such as superoxide dismutase (SOD), are candidate drugs for controlling this. This study from 2004 was designed to determine the therapeutic value of antioxidant enzymes in an experimental model of colitis, and to study the mechanisms underlying its effects on intestinal inflammation.

Effects of an oral superoxide enzyme supplementation of indices of oxidative stress, proviral load, and CD4-CD8 ratios in asymptomatic FIV-infected cats
This study from 2008 was designed to test the effect of antioxidant supplementation on feline immunodeficiency virus (FIV)-infected felines (essentially, a virus that inferes with a cat’s immune system). Antioxidant supplementation resulted in an increase in antioxidant enzyme levels. Scientists reported that further investigation needed to be done, with trials of antioxidant therapy in FIV-infected cats that were showing obvious symptoms of their disease, as well as in other feline patients where oxidative stress likely contributed to the development of disease.

Oral supplementation with melon superoxide dismutase extract promotes antioxidant defences in the brain and prevents stress-induced impairment of spatial memory
Aging leads to suppression of brain functions such as learning and memory. This effect is accelerated by chronic stress, especially psychological stress. This 2009 study was conducted on mice to investigate whether oral administration of antioxidant supplements could protect against stress-induced impairment of learning and memory. Scientists used two types of antioxidant enzymes – GliSODin and alpha-Tocopherol. These findings suggested that GliSODin is a useful antioxidant for prevention of stress-induced impairment of cognitive function.

The effect of postinjury administration of polyethylene glycol-conjugated superoxide dismutase (pegorgotein, Dismutec) or lidocaine on behavioral function
The obstruction of blood flow to the brain following a traumatic brain injury may contribute to further complications occurring as a result of trauma. The goal of this study from 1996 was to determine the benefits of administering an enzyme called PEG-SOD and the local anesthetic lidocaine after a trauma to reduce motor and cognitive deficits that could ensue.

Protection against oxygen toxicity by intravenous injection of liposome-entrapped catalase and superoxide dismutase
Scientists have used a number of approaches in their attempts to prevent the toxic effect of oxygen upon lungs. However, most have failed to have substantial impact. This experiment from 1983 determined that the use of specific enzymes (SOD- and catalase-containing liposomes) can decrease oxygen injury and can augment lung defenses against toxic oxygen levels.

Effect of superoxide dismutase on a rabbit model of chronic allergic asthma
This study, conducted in 1998, examined rabbits with chronic allergic asthma and tested whether treating with antioxidant enzymes (superoxide dismutase conjugated to polyethylene glycol) would protect the airways from oxygen radical injury, decrease airway inflammation, and weaken the asthmatic response. Results showed that this treatment led to improved airway responsiveness, but there was no significant effect on airway inflammation.

Therapeutic Effect of Lecithinized Superoxide Dismutase on Pulmonary Emphysema
In this 2011 trial, scientists examined the effect of antioxidant enzymes (PC-SOD) on elastase-induced pulmonary emphysema, an animal model of chronic obstructive pulmonary disease (COPD). The severity of the pulmonary inflammatory response and emphysema in mice was assessed by various criteria. Results suggested that PC-SOD protects against pulmonary emphysema by decreasing the levels of free radicals called superoxide anions within the lungs, which results in less inflammation. This study proposed that inhalation of PC-SOD is therapeutically beneficial for COPD.

Safety and pharmacokinetics of recombinant human superoxide dismutase administered intratracheally to premature neonates with respiratory distress syndrome
This study from 1995 examined using antioxidant enzymes (rhSOD) in the prevention of lung injury of newborn babies. 26 preterm infants with respiratory distress syndrome were studied and were given either a placebo or rhSOD. Data suggested that a single dose of rhSOD resulted in significant increases in both concentration and activity of the antioxidant in the newborn’s body. The enzyme appeared to be well tolerated.

Targeting of superoxide dismutase to the liver results in anti-inflammatory effects in rats with fibrotic livers
In 1999, a study was conducted to evaluate the effects of antioxidant enzymes (superoxide dismutase) on the liver. Results showed an anti-inflammatory response when the enzymes were given to rats with fibrotic livers. (Fibrosis indicates thickening and scarring of connective tissues.)

Dietary superoxide dismutase does not affect tissue levels
This study from 1983 examined the effects of dietary supplementation of antioxidant enzymes (superoxide dismutase) on the levels of antioxidants within the tissues of mice. Mice were divided into two groups; the control group received a complete purified diet, and the supplemented group received the same diet containing 0.004% superoxide dismutase. Results indicated that oral supplementation of antioxidant enzymes does not affect antioxidant levels within bodily tissues.

Superoxide dismutase and catalase as therapeutic agents for human diseases: A critical review
This 1989 article provided a comprehensive review about the literature dealing with antioxidant enzyme therapy. The discussion centered on new developments in pharmacology regarding therapeutic use of antioxidant enzymes, as well as disease areas not reviewed elsewhere, such as neurologic, pulmonary, ocular, gastrointestinal, oncologic, genitourinary, and others.


Analysis of the fecal microflora of human subjects consuming a probiotic product containing Lactobacillus rhamnosus DR20
Within the large intestine of humans is a complex community of tiny living organisms (called healthy bacteria) that is often referred to as “intestinal microflora”. Public interest in intestinal microflora was stimulated in the years prior to this study, largely due to the development and marketing of preparations of living microbial cells that, when consumed, are believed to benefit the health and well-being of the consumer. These preparations are known as “probiotics”. This study from 2000 reports on a long-term study in which healthy human subjects consumed a probiotic supplement, and scientists measured the subjects’ fecal microflora to test the impact of taking this product on a regular basis.

Biotherapeutic effects of probiotic bacteria on candidiasis in immunodeficient mice
In this study from 1997, four species of probiotic bacteria (Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus casei GG, or Bifidobacterium animalis) were assessed for their capacities to protect immunodeficient mice from candidiasis (yeast infections) of their digestive tracts. Each probiotic bacterial species colonized the gastrointestinal tracts of both strains of mice. Results showed that none of the probiotic bacteria completely prevented candidiasis, but B. animalis reduced its incidence and severity. Probiotics also modulated antibody- and cell-mediated immune responses to candidiasis.

Commensal anaerobic gut bacteria attenuate inflammation by regulating nuclear-cytoplasmic shuttling of PPAR-gamma and ReIA
The human gut microflora (tiny living organisms called healthy bacteria) is important in regulating host inflammatory responses and in maintaining immune balance. In this study from 2004, scientists hypothesized that commensal bacteria (normal bacteria that reside in the body) influence the body’s defense system by triggering the natural immune response from intestinal cells. To investigate this, they examined the inflammatory response effect of common gut bacteria when exposed to the bacteria Salmonella enterica serovar Enteritidis.

Effect of administration of Lactobacillus casei strain GG on the gastrointestinal microbiota of newborns
The aim of the study from 1993 was to determine whether the probiotic ‎Lactobacillus GG could colonize the intestine of newborns, and if this would impair the establishment of a community of healthy gut bacteria in the babies. The fecal bacterial population of 25 newborns was studied; in addition to breastfeeding, 15 babies (GG group) received the Lactobacillus GG supplement. 10 newborns (control group) did not receive any supplement to breastfeeding. The study showed that administration of Lactobacillus GG increased intestinal lactobacilli concentrations but did not impair the establishment of a normal gut bacterial community.

Effect of probiotics on gastrointestinal symptoms and small intestinal permeability in children with atopic dermatitis
This 2004 study was conducted in order to determine whether supplementing with probiotic lactobacilli would alleviate small intestinal inflammation and strengthen the intestinal barrier function in children with atopic dermatitis (eczema). During this supplementation, there was a significant decrease in gastrointestinal symptoms. Impairment of the intestinal mucosal barrier appeared to be involved in the development of eczema. The study suggested that probiotic supplementation could stabilize the intestinal barrier function and decrease gastrointestinal symptoms in children with eczema.

Escherichia coli serotypes throughout the gastrointestinal tract of patients with intestinal disorders
Improved techniques for studying bacteria have permitted a more in depth look at the microecology of the small intestine in humans. This 1977 study was conducted on seven patients with a variety of gastrointestinal disorders to determine whether the whole small intestine is colonized by a single strain of bacteria or multiple strains of this species. E. coli is the organism most widely studied because an international system exists (called serotyping) where distinct variations can be made within a species of bacteria. Findings concluded that a different single serotype of E. coli dominated the gastrointestinal tract of each of the patients studied.

Good adhesion properties of probiotics- a potential risk for bacteremia
Probiotics like Lactobacillus strains are generally regarded as safe due to their long history of safe use in fermented foods and, in many cases, their presence in a normal human gut. However, Lactobacillus strains have also been associated with some isolated cases of bacteremic infection (the presence of bacteria in the blood, which should always be sterile) in patients with immune suppression or underlying diseases. The ability of this bacteria to adhere to human intestinal mucus was tested in clinical blood cultures. The objective of this study from 2001 was to evaluate whether the ability of this bacteria to bind in high numbers to mucus is a property that promotes its passage into sites like the bloodstream and if this is a factor to consider when planning probiotic therapy.

Lactic acid bacteria inhibit TH2 cytokine production by mononuclear cells from allergic patients
Lactic acid bacteria (LAB), which are present in fermented foods and also reside in the human gut, have been shown to have beneficial effects on human health. Recent reports have indicated their capacity to reduce allergic symptoms. The purpose of this investigation from 2002 was to determine the effect of LAB on the production of type 2 cytokines (TH2), which characterize allergic diseases. The tested LAB strains exhibit an anti-TH2 activity, and thus different strains of this family might be useful in the prevention of allergic diseases.

Lactobacilli and bacteremia in southern Finland, 1989-1992
In order to assess the potential for probiotic bacteria to cause serious infections, a team in southern Finland over a four-year period (1989-1992) studied the prevalence of bacteremia due to Lactobacillus species. Bacteremia indicates the presence of bacteria in the blood, which should always be sterile. Among 3,317 blood culture isolates, lactobacilli were identified in eight patients. The results did not provide evidence that any particular species or subspecies of Lactobacillus was the cause of the infections; no infections caused by isolates similar to the recently-introduced dairy probiotic strain, Lactobacillus GG, were observed.

Lactobacilli differentially modulate expression of cytokines and maturation surface markers in murine dendritic cells
Dendritic cells (DC) play a pivotal immunoregulatory role in the T helper cell balance (immune response cells) and are present throughout the gastrointestinal tract. Thus, DC may be targeted for activation by gut bacteria, including ingested probiotics. In this 2002 study, scientists tested the hypothesis that species of Lactobacillus (important members of human gut bacteria) may differentially activate DC.

Lactobacillus bacteremia during a rapid increase in probiotic use of Lactobcillus rhamnosus GG in Finland
Lactobacilli (gut bacteria) supposedly have a low risk of causing disease; they are seldom detected in blood cultures. Lactobacillus rhamnosus GG, a bacteria which originates indigenously in the human intestine, became available for use as a probiotic in 1990 in Finland. Scientists in this 2002 study evaluated the possible effects of the increased probiotic use of L. rhamnosus GG on the occurrence of bacteremia due to lactobacilli. (Bacteremia indicates the presence of bacteria in the blood, which should always be sterile.) Results indicated that increased probiotic use of L. rhamnosus GG did not lead to an increase in Lactobacillus bacteremia.

Lactobacillus endocarditis cause by a probiotic organism
Probiotics are microorganisms deliberately ingested to modify the gut bacteria in order to produce health and well-being. In this study from 1999, scientists reported on what they believed to be the first case of endocarditis (an infection of the heart’s inner lining) due to Lactobacillus rhamnosus brought about by self-medication with a freeze-dried probiotic preparation, in a subject who was previously fit and well. Results suggested that there is less risk attached to the use of probiotic organisms such as L. acidophilus or Lactobacillus sp GG – but that use of probiotics like L. rhamnosus may be more risky than beneficial to health.

Lactobacillus GG effect in increasing IFN-gamma production in infants with cow’s milk allergy
Probiotic bacteria are potentially beneficial to maturation of the immune system of infants. The purpose of this 2004 study was to examine the role of probiotic bacteria in treatment of lactose intolerance and immunoglobulin E (IgE)-associated dermatitis (eczema). To do so, scientists investigated the effects of the probiotic Lactobacillus rhamnosus GG (LGG) and a mixture of four bacterial species on the body’s immune response.

Probiotics- A novel approach in the management of food allergy
The aim of this 1997 study was to build on previous studies indicating that human intestinal bacteria Lactobacillus GG promotes immune responses. This study had two parts: the first part evaluated the clinical and immunologic effects of cow’s milk elimination (without the addition of Lactobacillus GG) by giving an extensively hydrolyzed whey formula to infants with atopic eczema and an allergy to cow’s milk. The second part of the study involved 10 breast-fed infants who had atopic eczema and cow’s milk allergy. In this group, Lactobacillus GG was given to nursing mothers.

Probiotics and safety
Bacterial species that have traditionally been regarded as safe are used in probiotics; the main strains include lactic acid bacteria and bifidobacteria that inhabit the intestinal tracts of humans and animals. However, reports of frequent isolation of bacteria used in probiotics from infection sources have raised much debate over the safety of probiotics. This article from 2001 describes the status quo of isolation of probiotic bacteria from infections and also reviews each of the factors that have to be addressed in assessing the safety of probiotics: pathogenicity, infectivity, toxicity, and intrinsic properties of the bacteria.

Probiotics for treating infectious diarrhoea
Probiotics, which are live bacteria or yeasts, may offer a safe intervention in acute infectious diarrhea to reduce the duration and severity of the illness.To assess the effects of probiotics in proven or presumed infectious diarrhea, scientists conducted randomized controlled trials in 2009, comparing a specified probiotic agent with placebo or no probiotic in people with acute diarrhea that was caused by an infectious agent. Probiotics reduced the risk of diarrhea at three days and the mean duration of diarrhea by 30.48 hours.

Probiotics in Clinical Conditions
This article from 2002 summarized evidence for the positive effects of probiotics in various clinical situations. The clinical situations included prevention or treatment of antibiotic-associated disorders, gastroenteritis, diarrhea, lactose intolerance, intestinal infections, irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), colonic cancer, to name a few. Strong evidence for the positive effects of some probiotics in specific clinical situations supported further research.

Probiotics in prevention of antibiotic associated diarrhoea- meta-analysis
“Probiotic” was first used to describe “a live microbial supplement, which beneficially affects the host”. Since then, research has looked at possible clinical uses for these bacteria. In 1995, when greater understanding of their properties had developed, the term “biotherapeutic agents” was proposed to describe microorganisms with specific therapeutic properties that also inhibit the growth of disease-causing bacteria. Streptococcus thermophilus and Lactobacillus bulgaricus, commonly used in the dairy food industry, were among the first bacteria to be studied, but many other strains have been used as well. In this study, conducted in 2002, scientists reviewed the results from various trials carried out to study the benefits of these probiotics.

Probiotics in primary prevention of atopic disease- a randomized placebo-controlled trial
This study from 2001 assessed the effect of the probiotic Lactobacillus GG (which is safe at an early age and effective in treatment of allergic inflammation and food allergy) on atopic disease. “Atopic” refers to having a hereditary predisposition to developing allergic reactions. Lactobacillus GG was effective in prevention of early atopic disease in children at high risk. Thus, gut bacteria might be a source of natural immunomodulators and probiotics, for prevention of atopic disease.

Safety and tolerance of Lactobacillus reuteri supplementation to a population infected with the human immunodeficiency virus

Safety of probiotics that contain lactobacilli or bifidobacteria
The bacteria lactobacilli and bifidobacteria are extremely rare causes of infection in humans, as are the probiotics based on these organisms. However, because there are published reports of infections involving lactobacilli or bifidobacteria, including two cases suggested to be associated with probiotic strains, it was considered important to develop a science-driven, evidence-based overview of the safety of lactobacilli and bifidobacteria used as probiotics in foods. This overview was written in 2002.

Small Intestinal Bacterial Overgrowth- Roles of Antibiotics, Prebiotics, and Probiotics
Though a vibrant community of healthy bacteria within the gut is good, it’s possible to have too much of a good thing. Small intestinal bacterial overgrowth (SIBO) is something that occurs when there is an overgrowth of the various types of bacteria that should normally be found in the colon. SIBO is common in intestinal failure. Its occurrence relates to issues with intestinal anatomy, the intestine’s ability to move and contract, and gastric acid secretion. The accurate diagnosis of bacterial overgrowth has presented a number of challenges in clinical practice and especially so among patients with intestinal failure. This study from 2006 examined the roles of antibiotics, prebiotics and probiotics in patients possibly experiencing SIBO.

Bacillus subtilis

The Intestinal Life Cycle of Bacillus subtilis and Close Relatives
Bacillus subtilis is considered a soil organism for which endospore formation provides a means to ensure long-term survival in the environment. Spores of Bacillus species are found also in dust, water, and in the air. In this study from 2006, scientists analyzed what happened when a spore when ingested. The findings showed the entire intestinal life cycle of B. subtilis and suggested that other Bacillus species could also be members of the gut bacteria.

The Safety of Bacillus subtilis and Bacillus indicus as food probiotics
This 2007 study was conducted on the safety of two species of the healthy bacteria Bacillus; one of which, Bacillus subtilis, is in current use as a food supplement. Findings indicated that Bacillus indicus and B. subtilis should be considered safe for oral use, although there was a resistance of B. indicus to clindamycin (an antibiotic used for serious infections caused by bacteria), which scientists said required further study.

The Safety of Two Bacillus Probiotic Strains for Human Use
Probiotics based on Bacillus strains (a healthy bacteria) have been increasingly proposed for prophylactic (disease prevention) and therapeutic use against several gastrointestinal diseases. This 2007 study was conducted on the safety of two Bacillus strains included in a popular East European probiotic. Bacillus subtilis strain was sensitive to all antibiotics listed by the European Food Safety Authority. Bacillus licheniformis strain was resistant to chloramphenicol and clindamycin antibiotics. Results indicated that while certain risks existed for the B. licheniformis strain since it is antibiotic resistant, B. subtilis strain could be considered as non-pathogenic and safe for human consumption.


These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease. The information contained in this website is intended for educational purposes only. If you are currently taking medications, or have other health-related conditions, consult a physician before adding supplements to your diet.


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