Bacterial Cytotoxins refer to the cytolethal distending toxin, subunit B (CdtB) that is released by Escherichia coli, Salmonella, Shigella and Campylobacter jejuni. Utilizing subunits A and C, gram-negative bacteria can bind to human cells, allowing CdtB to infiltrate the cell. Inside the cell, CdtB contributes to cytoskeletal damage, which may induce apoptosis (cell death). CdtB is the first bacterial toxin known to act in the nucleus of a target cell.

Associated With:

- Irritable bowels

- SIBO

- Gut dysbiosis

- Chronic functional bowel changes

- Localized aggressive periodontitis

Bacteroidales are a large group of gut bacteria that play key roles in digestion, carbohydrate breakdown, and maintaining microbial balance. Healthy levels support nutrient absorption and a stable microbiome. Low or high levels can signal shifts in diet, inflammation, dysbiosis, or overall gut function.

Species in the genus Bacteroides carry out broad metabolic functions, including degradation of complex plant polysaccharides, proteolytic activities, de-conjugation of bile acids, mucosal barrier integrity, short chain fatty acid production, fatty acid storage and glucose metabolism. 

Species in the genus Bacteroides carry out broad metabolic functions, including degradation of complex plant polysaccharides, proteolytic activities, de-conjugation of bile acids, mucosal barrier integrity, short chain fatty acid production, fatty acid storage and glucose metabolism. 

Bacteroides caccae is a normal gut bacterium that supports digestion and helps break down complex carbohydrates. Healthy levels are part of a balanced microbiome. Shifts—either low or high—can indicate changes in microbial diversity, inflammation, diet, or overall digestive health.

Species in the genus Bacteroides carry out broad metabolic functions, including degradation of complex plant polysaccharides, proteolytic activities, de-conjugation of bile acids, mucosal barrier integrity, short chain fatty acid production, fatty acid storage and glucose metabolism.

Bacteroides spp. are maintained at a higher abundance in breastfed individuals into adulthood.

Bacteroides fragilis plays an important role in the prevention of intestinal inflammation. An energy-restricted diet has been shown to increase B. fragilis in overweight adolescents. An increase in B. stercoris has been associated with higher risk of colon cancer. Decreased levels of Bacteroides spp. have been reported in association with multiple sclerosis, rheumatoid arthritis and Parkinson’s disease.

Species in the genus Bacteroides carry out broad metabolic functions, including degradation of complex plant polysaccharides, proteolytic activities, de-conjugation of bile acids, mucosal barrier integrity, short chain fatty acid production, fatty acid storage and glucose metabolism.

Bacteroides spp. are maintained at a higher abundance in breastfed individuals into adulthood.

Bacteroides fragilis plays an important role in the prevention of intestinal inflammation. An energy-restricted diet has been shown to increase B. fragilis in overweight adolescents. An increase in B. stercoris has been associated with higher risk of colon cancer. Decreased levels of Bacteroides spp. have been reported in association with multiple sclerosis, rheumatoid arthritis and Parkinson’s disease.

Species in the genus Bacteroides carry out broad metabolic functions, including degradation of complex plant polysaccharides, proteolytic activities, de-conjugation of bile acids, mucosal barrier integrity, short chain fatty acid production, fatty acid storage and glucose metabolism.

Bacteroides spp. are maintained at a higher abundance in breastfed individuals into adulthood.

Bacteroides fragilis plays an important role in the prevention of intestinal inflammation. An energy-restricted diet has been shown to increase B. fragilis in overweight adolescents. An increase in B. stercoris has been associated with higher risk of colon cancer. Decreased levels of Bacteroides spp. have been reported in association with multiple sclerosis, rheumatoid arthritis and Parkinson’s disease.

Gram-negative species of the Bacteroidetes phylum. Immune-modulating normal gut species. Believed to be involved in microbial balance, barrier integrity, and neuroimmune health (Hsiao 2013). High levels may result from reduced digestive capacity or constipation. Low levels may contribute to reduced anti-inflammatory activity in the intestine.

Bacteroides ovatus had been shown to elicit the largest IgG and IgA responses in Crohn’s patients of the commensal bacteria.

Why Bacteroides ovatus induces such as response is not totally known, but it does produce esterase and lipase which can be potentially hazardous to the intestinal tissue, especially if initial damage has been created by a bacterial toxin such as Enterotoxigenic Bacteroides fragilis (ETBF). Bacteriodes ovatus plays an important role of degrading inulin, which the metabolites of in turn feeds Bacteroides vulgatus and supports the colony, so they have a syntrophic relationship

Bacteroides pectinophilus contributes to breakdown of dietary pectins which are prebiotics. Pectins are complex, plantderived carbohydrates that are indigestible by human enzymes, but can be easily degraded by certain commensal bacteria in the gut.

Species in the genus Bacteroides carry out broad metabolic functions, including degradation of complex plant polysaccharides, proteolytic activities, de-conjugation of bile acids, mucosal barrier integrity, short chain fatty acid production, fatty acid storage and glucose metabolism. 

The predominant genera in the human colonic microbiota are Bacteroides and Prevotella, which belong to the major phyla Bacteroidetes.

Species in the genus Bacteroides carry out broad metabolic functions, including degradation of complex plant polysaccharides, proteolytic activities, de-conjugation of bile acids, mucosal barrier integrity, short chain fatty acid production, fatty acid storage and glucose metabolism. Bacteroides spp. are maintained at a higher abundance in breastfed individuals into adulthood.

Bacteroides uniformis is a fiber-degrading bacteria. It colonizes the gut in early infancy and is promoted by breast feeding.

Thought to enhance the gut barrier through the production of butyrate and GABA. Also produces beta glucuronidase, degrades mucin, and produces folate.

Studied in preclinical trials as a potential probiotic for use in inflammatory and metabolic disorders.

B. uniformis was found to be decreased in obese patients as compared to healthy or lean groups. It was higher in healthy controls as compared to patients with ulcerative colitis.

Enriched in healthy individuals versus colorectal cancer patients.

Associated with degradation of the isoflavone genistein, which then becomes less bioavailable to the human.