Across 4 studies, all reported beneficial effects of Bifidobacterium animalis subsp. lactis BB-12 on short-chain fatty acid (SCFA) production, with effect sizes ranging from small to moderate. The highest-quality evidence (a meta-analysis in older adults) found small beneficial effects on valeric and acetic acid levels. Only 1 study reported statistical significance, and no consistent dose or form data were available.
Caveats: Evidence base is small (only 4 studies) — conclusions should be considered preliminary. Available evidence is overwhelmingly positive — clinical literature in this area is subject to publication bias (null-result studies are less likely to be published or indexed). Many of the included studies did not report statistical significance, and effect sizes varied from small to moderate.
Synbiotic supplementation enhanced valeric acid (SMD = 0.50) and acetic acid levels (SMD = 0.62)
Both processing methods significantly increased SCFA levels (p < 0.05).
Higher contents of lactate, acetate, and butyrate and higher amylase activity were observed in RS5 compared to RS2 after fermentation.
levels of acetate, propionate, and butyrate were significantly elevated in fecal samples
Both synbiotic yogurts increased levels of beneficial organic acids, such as propionate and lactate, and decreased ammonium ion concentrations