Probiotics for adults
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Probiotics for Adults: Health Benefits and Efficacy
Gut Health and Microbiota
Probiotic supplementation in healthy adults has been shown to transiently improve gut microbiota by increasing the concentration of supplement-specific bacteria. However, these changes are not persistent 1. Studies have demonstrated that probiotics can enhance intestinal function, increase fecal lactic acid bacteria, and improve stool consistency and bowel movement frequency 16. Specifically, multispecies probiotics are more effective in reducing gut transit time and increasing stool frequency compared to single-species probiotics 34.
Immune System Response
Probiotics have been found to bolster the immune system in healthy adults. They can improve immune responses, as evidenced by increased serum levels of brain-derived neurotrophic factor (BDNF) and reduced inflammation-causing gut bacteria 12. This suggests that probiotics may play a role in enhancing overall immune function and reducing inflammation.
Cognitive Function and Mood
Probiotics have shown promise in improving cognitive function and mood in older adults. A study found that probiotics containing Bifidobacterium bifidum and Bifidobacterium longum significantly improved mental flexibility and stress scores, along with increasing serum BDNF levels 2. Another study demonstrated that Lactobacillus plantarum P8 could alleviate stress and anxiety while enhancing memory and cognitive traits in stressed adults 5.
Gastrointestinal Discomfort and Constipation
Probiotics are effective in alleviating gastrointestinal discomfort and functional constipation. Meta-analyses have shown that probiotics can significantly reduce gut transit time, increase stool frequency, and improve stool consistency 34. These benefits are more pronounced with multispecies probiotics compared to single-species formulations.
Female Reproductive Health
Probiotic supplementation has been linked to improvements in female reproductive health, particularly in increasing vaginal lactobacilli concentration 1. This can help maintain a healthy vaginal microbiota, potentially reducing the risk of infections.
Cardiovascular Health
The evidence supporting the role of probiotics in improving blood lipid profiles and reducing cardiovascular disease risk in healthy adults is insufficient. More research is needed to establish any significant benefits in this area 1.
Oxidative Stress
Probiotics and synbiotics have been shown to improve biomarkers of oxidative stress. Supplementation can significantly increase serum total antioxidant capacity (TAC), glutathione (GSH), and nitric oxide (NO) levels, while reducing malondialdehyde (MDA) levels, indicating a reduction in oxidative stress 8.
Conclusion
Probiotics offer several health benefits for adults, including improvements in gut health, immune function, cognitive performance, and gastrointestinal comfort. While the evidence is strong for some areas, such as gut health and immune response, more research is needed to confirm benefits in cardiovascular health and persistent changes in gut microbiota. Overall, probiotics can be a valuable addition to a healthy diet, particularly for enhancing gut and immune health.
Sources and full results
Most relevant research papers on this topic
A review of probiotic supplementation in healthy adults: helpful or hype?
Probiotic supplementation in healthy adults can improve immune system responses, gut microbiota concentration, and gastrointestinal health, but does not consistently cause persistent changes or improve blood lipid profile.
Systematic Review
Rigorous Journal
Highly CitedProbiotic Supplementation Improves Cognitive Function and Mood with Changes in Gut Microbiota in Community-Dwelling Older Adults: A Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial
Probiotics improve mental flexibility and reduce stress in healthy older adults, while also causing changes in gut microbiota.
RCTHighly CitedMeta-analysis of randomized controlled trials of the effects of probiotics on functional constipation in adults.
Probiotics, particularly multispecies probiotics, can significantly reduce gut transit time, increase stool frequency, and improve stool consistency in adults with functional constipation.
Meta-Analysis
Very Rigorous JournalHighly CitedThe effect of probiotics on functional constipation in adults: a systematic review and meta-analysis of randomized controlled trials.
Probiotics may improve gut transit time, stool frequency, and stool consistency in adults with functional constipation, but more rigorous research is needed to determine the most effective strains, doses, and duration of use.
Meta-AnalysisVery Rigorous JournalHighly CitedProbiotic Lactobacillus plantarum P8 alleviated stress and anxiety while enhancing memory and cognition in stressed adults: A randomised, double-blind, placebo-controlled study.
Probiotic Lactobacillus plantarum P8 effectively reduces stress and anxiety while enhancing memory and cognition in stressed adults.
RCTVery Rigorous JournalHighly CitedOral administration of two probiotic strains, Lactobacillus gasseri CECT5714 and Lactobacillus coryniformis CECT5711, enhances the intestinal function of healthy adults.
Probiotics, Lactobacillus gasseri CECT5714 and Lactobacillus coryniformis CECT5711, can improve intestinal function in healthy adults without causing adverse effects.
RCTHighly CitedProbiotics for treatment of Clostridium difficile-associated colitis in adults.
Probiotics show insufficient evidence to recommend as an adjunct to antibiotic therapy for C. difficile colitis, and there is no evidence to support their use alone in the treatment of C. difficile colitis.
Systematic ReviewHighly CitedThe effects of probiotic/synbiotic supplementation compared to placebo on biomarkers of oxidative stress in adults: a systematic review and meta-analysis of randomized controlled trials
Probiotic/synbiotic supplementation significantly increases serum antioxidant capacity, glutathione, and nitric oxide levels, and reduces malondialdehyde levels in adults, potentially improving antioxidant indices and reducing oxidative stress.
Meta-AnalysisEffects of probiotic supplementation on the gut microbiota composition of adults: a systematic review of randomized clinical trials.
Probiotic supplementation showed no consistent effects on gut microbiota composition in adults, with only one study showing significant effects.
Systematic ReviewProbiotics for the prevention of Clostridium difficile-associated diarrhea in adults and children.
Probiotics show potential in preventing Clostridium difficile-associated diarrhea in adults and children, but more research is needed to confirm their effectiveness and safety.
Meta-AnalysisVery Rigorous JournalHighly Cited