Galacto-Oligosaccharides Exert Bifidogenic Effects at Capsule-Compatible Ultra-Low Doses

Prebiotics are selectively used by host microorganisms to promote health. Because effective prebiotic doses (1.5-30 g/day) often require inconvenient delivery formats, this study aims to explore whether capsule-compatible doses of galacto-oligosaccharides (GOS) can effectively modulate the gut microbiome.

The impact of Bimuno^® GOS (Reading, UK) at 0.5, 0.75, 1.83, and 3.65 g on the adult gut microbiome was assessed using the ex vivo SIFR^® technology (n = 8), a clinically validated, bioreactor-based technology.

The GOS were rapidly fermented and significantly increased beneficial Bifidobacterium species (B. adolescentis, B. bifidum, and B. longum), even at the lowest tested dose. In doing so, GOS strongly promoted SCFA production, particularly acetate (significant from 0.5 g) and butyrate (significant from 0.75 g). Gas production only mildly increased, likely as Bifidobacterium species do not produce gases. Based on the ability of the SIFR^® technology to cultivate strictly anaerobic, hard-to-culture gut microbes, unlike in past in vitro studies, we elucidated that GOS also enriched specific Lachnospiraceae species. Besides Anaerobutyricum hallii, this included Bariatricus comes, Blautia species (B. massiliensis, Blautia_A, B. faecis), Oliverpabstia intestinalis, Mediterraneibacter faecis, and Fusicatenibacter species. Finally, GOS also promoted propionate (significant from 0.75 g), linked to increases in Phocaeicola vulgatus.

GOS displayed prebiotic potential at capsule-compatible doses, offering greater flexibility in nutritional product formulation and consumer convenience. Notably, the strong response at the lowest dose suggests effective microbiome modulation at lower levels than previously expected.