Probiotics, Fermentation, and Gut Health: Key Concepts and Food Sources

Probiotics

Live microbial supplements that positively affect the host's health by improving intestinal microbial balance.

Lactobacillus

A type of probiotic bacteria found in the ileum (last section of small intestine).

Bifidobacteria

A type of probiotic bacteria found in the large intestine.

Kefir grains

A mixture of bacteria and yeast clumped with casein and complex sugars.

Lactic acid bacteria

Used for food preservation through fermentation.

Yogurt and curds

Made in a controlled environment by adding live cultures.

Antibiotics

Can wipe out good gut bacteria.

Lacto-fermentation

A process where natural bacteria feed on sugar and starch to create lactic acid, preserving food and creating beneficial enzymes, vitamins, and probiotics.

Fermentation

A process based on the growth of microorganisms in foods.

Tempeh

Made from fermented whole soybeans.

Kombucha

A fermented tea.

SCOBY

Symbiotic Colony of Bacteria & Yeast.

Vegetables

Can be fermented.

Commercial sauerkraut

May lack probiotics because processing may kill them.

Miso

A fermented Japanese seasoning used in soups.

Probiotics and pathogens

Probiotics inhibit pathogens by consuming nutrients they need and not giving them space to adhere to the intestine.

Criteria for bacteria to be probiotic

Not harmful, survives processing and digestion, remains alive in the gut, elicits a gut response, provides health benefits.

Other probiotics

Examples include E. coli, bacillus

E. coli

A type of bacteria.

Bacillus

A genus of bacteria.

Saccharomyces boulardii

A type of yeast.

Characteristics of probiotics

Human origin, acid/bile resistant, attach to epithelial cells, colonize gut, produce antimicrobial substances, boost immunity, safe and documented benefits.

Prebiotics

Non-digestible food ingredients that stimulate growth/activity of beneficial gut microbiota.

Common prebiotics

Inulin, oligofructose, polydextrose.

Foods containing oligofructose

Wheat, onions, bananas, honey, garlic, leeks, chicory root.

Strongest clinical evidence for probiotics

Improving gut health and stimulating immune function.

Probiotics and diarrhea

Reduce duration of gastroenteritis and frequency of diarrhea; S. boulardii reduces antibiotic-associated diarrhea.

Probiotic that may help lower body fat

Lactobacillus.

Probiotics and IBD

Influence the colonic immune system.

Probiotic useful for Crohn's disease

S. boulardii.

Benefits of probiotics beyond gut health

May prevent urinary tract infections and allergies.

Probiotic that reduces atopic eczema in children

Bifidobacterium.

Probiotics and cancer prevention

Probiotics reduce procarcinogens; prebiotics produce protective fatty acids in the colon.

Synbiotics

Combinations of probiotics and prebiotics that may reduce colorectal cancer.

Probiotics and ulcers

By reducing H. pylori in the stomach.

Potential risk of probiotics

Impaired cognition from bacterial overgrowth in the small intestine.

Probiotics necessity for healthy individuals

No.

Best natural sources of probiotics

Yogurt, kefir, fermented vegetables.

Fiber in heavily processed foods

No, very little.