PREBIOTICS/PROBIOTICS

Efficacy of Probiotic Compounds in Relieving Constipation and Their Colonization in Gut Microbiota
This study investigated how a combination of probiotic strains helped relieve constipation. The probiotics improved constipation symptoms by increasing stool number and weight, speeding up intestinal movement, and balancing gut-related hormones and immune factors. Some strains were able to colonize the gut, especially at higher doses, and their presence lasted even after treatment ended. The combined use of different probiotic strains appeared more effective than using a single type. Overall, the research suggests that using a mix of probiotics could be a promising approach to treat constipation by improving gut microbiota and digestive function.

How Prebiotics Help Gut Health
Prebiotics are non-digestible food components, such as resistant starch found in foods like oats, bananas, and garlic, that serve as nourishment for beneficial gut bacteria. These bacteria, when fuelled by prebiotics, produce short-chain fatty acids and other beneficial compounds that support gut health by strengthening the gut lining, reducing inflammation, and enhancing immune function. Inadequate intake of prebiotics can lead gut bacteria to consume the protective mucus layer of the gut, potentially resulting in inflammation and compromised gut health. Therefore, incorporating a variety of prebiotic-rich foods into the diet is essential for maintaining a healthy gut microbiome and overall well-being.

Effect of oral consumption of probiotic Lactobacillus planatarum P-8 on fecal microbiota, SIgA, SCFAs, and TBAs of adults of different ages
This study involved 33 participants categorized into three age groups: young (mean age 26), middle-aged (mean age 51), and elderly (mean age 76). Each participant consumed a daily dose of Lp-8 (6 × 10⁹ colony-forming units) for four weeks. The results indicated that Lp-8 supplementation led to significant alterations in the fecal microbiota, including increased levels of beneficial bacteria. Additionally, there were notable changes in the concentrations of SCFAs and TBAs, which are important for gut health and metabolism. The study also observed variations in the immune marker SIgA across different age groups, suggesting that age may influence the probiotic response.

Effect of Lactobacillus reuteri (DSM 17938) on methane production in patients affected by functional constipation: a retrospective studyEffect of oral consumption of probiotic Lactobacillus planatarum P-8 on fecal microbiota, SIgA, SCFAs, and TBAs of adults of different ages
This study involved 33 participants categorized into three age groups: young (mean age 26), middle-aged (mean age 51), and elderly (mean age 76). Each participant consumed a daily dose of Lp-8 (6 × 10⁹ colony-forming units) for four weeks. The results indicated that Lp-8 supplementation led to significant alterations in the fecal microbiota, including increased levels of beneficial bacteria. Additionally, there were notable changes in the concentrations of SCFAs and TBAs, which are important for gut health and metabolism. The study also observed variations in the immune marker SIgA across different age groups, suggesting that age may influence the probiotic response.

The effect of probiotics on functional constipation in adults: a systematic review and meta-analysis of randomized controlled trials
This systematic review and meta-analysis included 14 randomized controlled trials with a total of 1,182 participants. The study found that probiotics significantly reduced whole gut transit time by 12.4 hours and increased stool frequency by 1.3 bowel movements per week. Notably, the probiotic strain Bifidobacterium lactis was particularly effective, whereas Lactobacillus casei Shirota showed no significant effect on stool frequency. Probiotics also improved stool consistency. No serious adverse events were reported, although the studies had high attrition and reporting bias. The authors concluded that probiotics, especially B. lactis, may be beneficial for managing functional constipation, but further well-designed trials are needed to confirm these findings.

Production of gamma-aminobutyric acid (GABA) by Lactobacillus buchneri isolated from kimchi and its neuroprotective effect on neuronal cells
The article reports on the ability of certain lactic‑acid bacteria from fermented foods (such as kimchi) to produce Gamma‑aminobutyric acid (GABA). The authors found that some of these bacteria — when provided with glutamate — convert it into GABA, a compound with potential benefits for the nervous system. The findings suggest that fermented foods containing GABA‑producing bacteria might be a natural dietary source of GABA.

Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve
The study found that mice given a probiotic bacterium, Lactobacillus rhamnosus (JB‑1), showed altered expression of GABA receptor subunits in multiple brain regions — including increased expression in some cortical areas and decreased expression in regions such as the hippocampus and amygdala. PMC+1 Mice receiving the probiotic also exhibited reduced stress‑induced corticosterone levels and fewer anxiety‑ and depression‑like behaviors.

Probiotics’ Effects in the Treatment of Anxiety and Depression: A Comprehensive Review of 2014–2023 Clinical Trials
The review examines research from the past decade on whether probiotics can help improve symptoms of anxiety and depression by influencing the gut microbiome and the so‑called gut–brain axis. The authors conclude that most studies suggest a beneficial effect of probiotic use on mental health, though not all findings are consistent. They note promising evidence for probiotics as a novel, potentially personalised approach for mood disorders—but highlight the need for more precise data on exactly which probiotic strains, doses, and treatment lengths work best, and how outcomes vary with severity of symptoms.

Prebiotic intake reduces the waking cortisol response and alters emotional bias in healthy volunteers
The study tested whether taking prebiotics — inulin‑type fructooligosaccharides (FOS) or galactooligosaccharides (B‑GOS) — could affect stress hormones and emotional processing in healthy adults. After three weeks of B‑GOS supplementation (but not FOS), participants showed a lower morning cortisol awakening response (a stress hormone marker) and a shift in emotional bias away from negative toward more positive stimuli. The authors suggest that certain prebiotics might help reduce stress reactivity and influence mood by modulating the gut microbiome.