Probiotic Evidence

PROBIOTIC EVIDENCE
The following probiotic strains have been studied in randomized controlled trials (RCTs),
meta-analyses, or clinical studies for improving gut barrier integrity (reducing leaky gut,
enhancing mucin production, or tightening junctions) and supporting the gut-brain axis
(reducing anxiety, depression, stress, or improving cognition) (Frontiers, 2024;
Nutrients, 2023). I prioritize strains with human clinical data, focusing on mental health
and gut health outcomes.
1. Lactobacillus rhamnosus GG (LGG)
 Gut Lining Benefits:
o Enhances gut barrier integrity by upregulating tight junction proteins and
mucin production.
o Reduces intestinal permeability in IBS patients.
o Links: Lactobacillus rhamnosus GG prevents epithelial barrier dysfunction
induced by interferon-gamma and fecal supernatants from irritable bowel
syndrome patients in human intestinal enteroids and colonoids - PubMed
o Lactobacillus rhamnosus GG supernatant promotes intestinal mucin
production through regulating 5-HT4R and gut microbiota - PubMed
o A randomized controlled trial of Lactobacillus GG in children with
functional abdominal pain - PubMed

 Gut-Brain Axis Benefits:
o Improves depression symptoms.
o Reduces anxiety and cortisol levels.
o Maintains neurotransmitter balance.
o Enhances cognitive performance in middle-aged and older adults.
o Links: Lactobacillus rhamnosus: An emerging probiotic with therapeutic
potential for depression - ScienceDirect
o Probiotics’ Effects in the Treatment of Anxiety and Depression: A
Comprehensive Review of 2014–2023 Clinical Trials - PMC
o Lactobacillus rhamnosus: An emerging probiotic with therapeutic potential
for depression - ScienceDirect

o Randomized Clinical Trial Examining the Impact of Lactobacillus
rhamnosus GG Probiotic Supplementation on Cognitive Functioning in
Middle-aged and Older Adults - PMC
2. Lactobacillus plantarum (e.g., DR7, 299v, OLL 2712)
 Gut Lining Benefits:
o Upgrades gut barrier function and helps prevent inflammatory bowel
disease (IBD).
o Normalizes digestive functions in patients with irritable bowel syndrome
(IBS).
o Improves intestinal flora.
o Reduces inflammation.
o Modulates the immune system.
o Progress on the mechanisms of Lactobacillus plantarum to improve
intestinal barrier function in ulcerative colitis - ScienceDirect
o The Benefits and Applications of Lactobacillus plantarum in Food and
Health: A Narrative Review - PMC
o Mechanisms of Health Improvement by Lactiplantibacillus plantarum
Based on Animal and Human Trials: A Review

 Gut-Brain Axis Benefits:
o Helps produce neurotransmitters such as serotonin and GABA.
o Decreases stress and anxiety symptoms.
o Reduces depressive symptoms.
o Improves cognitive function in patients with cognitive impairment.
o Improves sleep quality.
o Reduces fatigue.
o The Benefits and Applications of Lactobacillus plantarum in Food and
Health: A Narrative Review - PMC
o The Health Benefits of Probiotic Lactiplantibacillus plantarum: A
Systematic Review and Meta-Analysis | Probiotics and Antimicrobial
Proteins
o Probiotics’ Effects in the Treatment of Anxiety and Depression: A
Comprehensive Review of 2014–2023 Clinical Trials - PMC

 Other Benefits:
o Reduces body weight and abdominal fat.

o Improves insulin resistance.
o Improves oral health.
o Reduces HbA1c and blood pressure in patients with type 2 diabetes.
o Reduces total cholesterol, LDL (‘bad’ cholesterol), and triglyceride levels.
o Increases HDL (‘good’ cholesterol).
o Improves atopic dermatitis, acne and skin aging.
o Effect of Lactobacillus plantarum LMT1-48 on Body Fat in Overweight
Subjects: A Randomized, Double-Blind, Placebo-Controlled Trial - PMC
o The Role of Lactobacillus plantarum in Reducing Obesity and
Inflammation: A Meta-Analysis - PMC
o The Health Benefits of Probiotic Lactiplantibacillus plantarum: A
Systematic Review and Meta-Analysis | Probiotics and Antimicrobial
Proteins
3. Lactobacillus acidophilus
 Gut Lining Benefits:
o Strengthens the gut barrier.
o Reduces gut inflammation.
o Helps prevent and treat intestinal disorders.
o Helps digest lactose.
o Helps to break down food, reducing abdominal discomfort.
 Gut-Brain Axis Benefits:
o Helps regulate neurotransmitter activity.
o Decreases stress and anxiety symptoms.
o Reduces depressive symptoms.
o
 Other Benefits:
o Regulates the immune system.
o Reduces inflammation.
o Reduces body weight and abdominal fat.
o Improves insulin resistance and carbohydrate metabolism.
o Inhibits heart disease progression.
 Links:

 Lactobacillus and intestinal diseases: Mechanisms of action and
clinical applications - ScienceDirect
 (PDF) Probiotic significance of Lactobacillus strains: a
comprehensive review on health impacts, research gaps, and
future prospects

 Probiotics’ Effects in the Treatment of Anxiety and Depression: A
Comprehensive Review of 2014–2023 Clinical Trials - PMC
 The Functional Roles of Lactobacillus acidophilus in Different
Physiological and Pathological Processes - PMC

4. Bifidobacterium bifidum
 Gut Lining Benefits:
o Strengthens the gut barrier.
o Stops pathogens adhering to the gut lining.
o Reduces antibiotic-associated diarrhea, constipation, IBS and IBD.
 Gut-Brain Axis Benefits:
o Reduces anxiety and depression symptoms.
o Increases brain-derived neurotrophic factor (BDNF).
o Helps regulate neurotransmitter activity.
 Other Benefits:
o Regulates the immune system.
o Reduces inflammation.
o Helps to reduce obesity, high cholesterol and diabetes.
o
 Links:
o Compendium of Bifidobacterium-based probiotics: characteristics and
therapeutic impact on human diseases - PMC
o Probiotic Bifidobacterium bifidum strains desialylate MUC13 and increase
intestinal epithelial barrier function | Scientific Reports
o Recent Development of Probiotic Bifidobacteria for Treating Human
Diseases - PMC
o Competitive exclusion of enteropathogens from human intestinal mucus
by Bifidobacterium strains with acquired resistance to bile--a preliminary
study - PubMed
o Probiotics’ Effects in the Treatment of Anxiety and Depression: A
Comprehensive Review of 2014–2023 Clinical Trials - PMC
o Bifidobacteria and Their Role as Members of the Human Gut Microbiota -
PMC

5. Bifidobacterium bifidum

 Gut Lining Benefits:
o Has anti-infection properties.
o Has anti-viral properties.
o Increases nutrient absorption.
o Reduces constipation.
o Reduces the symptoms of IBD and IBS.
 Gut-Brain Axis Benefits:
o Reduces anxiety and depression symptoms.
o Increases brain-derived neurotrophic factor (BDNF).
o Helps regulate neurotransmitter activity.
 Other Benefits:
o Regulates the immune system.
o Reduces inflammation.
o Helps to high cholesterol.
o Improves sleep quality, decreases daytime dysfunction, and increases
energy.
 Links:
o Probiotics’ Effects in the Treatment of Anxiety and Depression: A
Comprehensive Review of 2014–2023 Clinical Trials - PMC
o Recent Development of Probiotic Bifidobacteria for Treating Human
Diseases - PMC
o Bifidobacterium longum 1714 improves sleep quality and aspects of well-
being in healthy adults: a randomized, double-blind, placebo-controlled
clinical trial | Scientific Reports
o Compendium of Bifidobacterium-based probiotics: characteristics and
therapeutic impact on human diseases - PMC