Multi-Strain Probiotic Mixture Affects Brain Morphology and Resting State Brain Function in Healthy Subjects: An RCT

A double-blind, randomized, placebo-controlled crossover study. Researchers monitored 22 healthy adults over four weeks to assess the impact of a probiotic intervention containing Bifidobacterium longum, Lactobacillus helveticus, and Lactiplantibacillus plantarum.

The probiotic intervention led to significant changes in brain morphology and resting-state brain function, affecting the gray matter volume of regions associated with cognitive processing and emotional regulation. Functional connectivity within key brain networks, including the default mode, salience, and frontoparietal networks, was also altered. Psychological symptoms such as depression, anxiety, and sleep patterns showed trends of improvement.

WHY THIS MATTERS

These findings suggest that probiotic supplementation can influence brain structure and function, potentially supporting emotional well-being and cognitive health.

Effect of probiotic and prebiotic vs placebo on psychological outcomes in patients with major depressive disorder: A randomized clinical trial.

A placebo-controlled, double-blind, randomized clinical trial with 110 participants (ages 18–50) experiencing mild to moderate depression. Over eight weeks, subjects taking Bifidobacterium longum and Lactobacillus helveticus (10 billion CFU per sachet) alongside antidepressant medication were compared to a placebo group.

The results showed a significant decrease in Beck Depression Inventory (BDI) scores, indicating reduced self-reported depression symptoms in the probiotic group compared to placebo.

WHY THIS MATTERS

Probiotic supplementation may enhance the effects of antidepressant therapy, offering additional support for mood regulation.

Assessment of psychotropic-like properties of a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) in rats and human subjects.

A double-blind, placebo-controlled, randomized study involving 66 healthy human volunteers. Participants consumed 3 billion CFU of Bifidobacterium longum and Lactobacillus helveticus daily for 30 days, with psychological and physiological markers assessed throughout the study.

The probiotic intervention resulted in improvements in somatization, depression, and anger-hostility subscales compared to placebo. Significant reductions were observed in hospital anxiety and depression scores (HADS), as well as urinary free cortisol levels, a marker of stress response.

WHY THIS MATTERS

This study highlights the potential of probiotics to positively impact mental well-being by reducing stress and enhancing emotional balance.

Beneficial psychological effects of a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) in healthy human volunteers.

A secondary analysis of the previous study focused on 25 participants with low baseline urinary free cortisol levels, examining additional psychological measures.

The probiotic formulation not only improved overall anxiety and depression scores but also led to significant enhancements in perceived stress levels and symptoms related to obsessive-compulsive tendencies, anxiety, and paranoid ideation.

WHY THIS MATTERS

For individuals with heightened stress sensitivity, probiotics may offer additional benefits in reducing perceived stress and improving emotional resilience.

The Efficacy, Safety, and Tolerability of Probiotics on Depression: Clinical Results From an Open-Label Pilot Study.

A double-blind, randomized, placebo-controlled study on 10 participants (ages 18–65) diagnosed with major depressive disorder (MDD), not currently taking antidepressant medication. Over eight weeks, subjects received a daily dose of Bifidobacterium longum and Lactobacillus helveticus (3 billion CFU per sachet), with mood and sleep quality assessed throughout the trial.

The probiotic group showed significant reductions in depression severity as measured by the Montgomery-Åsberg Depression Rating Scale (MADRS) and the Quick Inventory of Depressive Symptomatology (QIDS-SR16). 

Additionally, anhedonia (the inability to experience pleasure) improved, along with reductions in Generalized Anxiety Disorder (GAD-7) scores. Sleep quality, assessed via the Pittsburgh Sleep Quality Index (PSQI), significantly improved by week 8.

WHY THIS MATTERS

These results suggest that probiotics may help alleviate symptoms of depression and anxiety while improving sleep quality, even in individuals not taking medication.

Probiotic food supplement reduces stress-induced gastrointestinal symptoms in volunteers: a double-blind, placebo-controlled, randomized trial. 

A double-blind, placebo-controlled, randomized study with 72 volunteers (ages 18–60) experiencing daily stress and at least two stress-related symptoms, such as anxiety, irritability, sleeping problems, or gastrointestinal disturbances. Participants consumed 3 billion CFU of Bifidobacterium longum and Lactobacillus helveticus for three weeks.

The probiotic intervention significantly reduced stress-induced gastrointestinal symptoms, including abdominal pain and nausea/vomiting, with no reported adverse effects.

WHY THIS MATTERS

Probiotics may help alleviate digestive discomfort linked to stress, supporting overall gut health and well-being.

Lactobacillus rhamnosus R11 consumed in a food supplement survived human digestive transit without modifying microbiota equilibrium as assessed by real-time polymerase chain reaction.

An open clinical trial investigating probiotic survival and microbiome impact. Fourteen healthy adults consumed Lactobacillus helveticus (800 million CFU) and Lactobacillus rhamnosus (8 billion CFU) for 12 days.

High levels of Lactobacillus rhamnosus were detected in stool samples of all participants, while Lactobacillus helveticus was recovered in one subject. No significant changes in microbiome homeostasis were observed.

WHY THIS MATTERS

This study confirms the survival of probiotics in the gut, supporting their potential for beneficial effects.

Chronic administration of a microencapsulated probiotic enhances the bioavailability of orange juice flavanones in humans.

A randomized, placebo-controlled trial investigating the impact of Bifidobacterium longum (1.46 billion CFU) on flavanone bioavailability from orange juice in 16 adults (ages 18–70) over four weeks.

Chronic probiotic intake enhanced the absorption of beneficial phytonutrients, while acute intake showed no significant effect.

WHY THIS MATTERS

Probiotics may improve nutrient absorption, potentially enhancing the benefits of certain dietary compounds.

Use of probiotics as an adjuvant to sequential H. pylori eradication therapy: impact on eradication rates, treatment resistance, treatment-related side effects, and patient compliance.

A randomized, placebo-controlled study assessing Bifidobacterium animalis subsp. lactis (7 billion CFU) in 159 subjects with Helicobacter pylori infections undergoing conventional therapy.

Probiotic supplementation significantly increased eradication rates compared to conventional therapy alone or therapy plus placebo.

WHY THIS MATTERS

Probiotics may enhance treatment effectiveness for common bacterial infections, such as H. pylori.

The comparition of the efficacy of two different probiotics in rotavirus gastroenteritis in children.

A randomized study of 75 children (ages 5 months–5 years) diagnosed with rotavirus gastroenteritis. Bifidobacterium animalis subsp. lactis (30 mg) was administered alongside oral rehydration therapy.

Children receiving probiotics experienced a shorter duration of diarrhea (4 days vs. 7 days) compared to those who only received rehydration therapy.

WHY THIS MATTERS

Probiotics may support faster recovery from gastrointestinal infections in young children.

Efficacy of synbiotic, probiotic, and prebiotic treatments for irritable bowel syndrome in children: A randomized controlled trial.

A double-blind, randomized study with 71 children (ages 4–16) diagnosed with irritable bowel syndrome (IBS). Participants received either Bifidobacterium animalis subsp. lactis (5 billion CFU) alone or combined with inulin (900 mg) for four weeks.

Both groups showed improved symptoms, including reduced bloating, abdominal fullness, and constipation, with the synbiotic group experiencing a higher rate of full recovery.

WHY THIS MATTERS

Probiotics and synbiotics may help alleviate IBS symptoms in children.

A Subjective Evaluation of the Effects of a Probiotic Formulation on Skin Quality in Young Adult Females: Open-Label Proof-of-Concept Study.

An open-label study with 35 women (ages 30–45) investigating the impact of Lactobacillus helveticus and Bifidobacterium longum (3 billion CFU) on skin health over eight weeks.

Results showed improvements in skin hydration, firmness, elasticity, and fine lines. Participants also reported better sleep quality and reduced stress.

WHY THIS MATTERS

Probiotic supplementation may support skin health and overall well-being.

Interactions of Lactic Acid Bacteria with Human Intestinal Epithelial Cells: Effects on Cytokine Production.

Lactobacillus rhamnosus demonstrated significant modulatory effects on cytokine production in the human intestinal epithelial cell (IEC) line HT-29. It effectively decreased IL-8 levels, particularly when grown in industrial medium. RANTES production was reduced when HT-29 cells were co-stimulated with TNF-α and IFN-γ, with the strongest effects observed in industrial medium. Additionally, Lactobacillus rhamnosus significantly down-regulated both TNF-α and TGF-β production while stimulating cell proliferation, confirming that IL-8 reduction was not due to cell toxicity. This strain also exhibited the highest level of adhesion to HT-29 cells, correlating with its potent modulation of cytokine production.

WHY THIS MATTERS

This suggests that Lactobacillus rhamnosus may help regulate inflammatory responses in the gut, potentially benefiting individuals with inflammatory conditions.

The impact of meals on a probiotic during transit through a model of the human upper gastrointestinal tract.

Lactobacillus helveticus, Lactobacillus rhamnosus, and Bifidobacterium longum exhibited the highest survival rates when consumed 30 minutes before or with a meal in an in vitro model of the upper gastrointestinal tract. In contrast, survival rates were significantly lower when probiotics were consumed 30 minutes after a meal. Survival in milk with 1% milk fat and oatmeal-milk gruel was notably higher compared to apple juice or water.

WHY THIS MATTERS

Understanding probiotic survival in different conditions can help optimize consumption for maximum benefits.

Probiotics reduce enterohemorrhagic Escherichia coli O157:H7- and enteropathogenic E. coli O127:H6-induced changes in polarized T84 epithelial cell monolayers by reducing bacterial adhesion and cytoskeletal rearrangements.

Pretreatment of Hep-2 and T84 epithelial cells with Lactobacillus helveticus and Lactobacillus rhamnosus resulted in a dose-dependent reduction in the adhesion of pathogenic E. coli strains, including E. coli O157:H7 and EPEC E2348/69. Additionally, probiotic pretreatment helped maintain epithelial barrier integrity by mitigating the drop in transepithelial electrical resistance (TER) caused by infection.

WHY THIS MATTERS

These findings suggest that probiotics may help protect against gut infections by strengthening the intestinal barrier.

Selection of a Bifidobacterium strain to complement resistant starch in a synbiotic yoghurt.

Bifidobacterium animalis subsp. lactis survived well in simulated gastrointestinal conditions and efficiently hydrolyzed resistant starch. In addition to resistant starch, the organism was able to utilize a range of prebiotics, including inulin, and fructo-, galacto-, soybean-, and xylo-oligosaccharides.

WHY THIS MATTERS

Probiotics' ability to utilize prebiotics supports gut microbiome diversity and digestive health.

Production of beta-glucosidase and hydrolysis of isoflavone phytoestrogens by Lactobacillus acidophilus, Bifidobacterium lactis, and Lactobacillus casei in soymilk.

Bifidobacterium animalis subsp. lactis was shown to hydrolyze isoflavone glycosides into aglycones, enhancing the bioavailability of these beneficial phytonutrients.

WHY THIS MATTERS

Probiotics may improve nutrient absorption, amplifying the health benefits of dietary phytonutrients.