Most human studies evaluating the effects of prebiotics have explored effects on the composition of the gastrointestinal microbiota. These studies report significant increases in Bifidobacterium and to a lesser-degree Lactobacillus bacterium and Faecalibacterium prausnitzi, Roseburia and Eubacterium spp. and their by-products.

The main prebiotics researched are fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS), lactulose and partially- hydrolysed guar gum.

Taking Lactulose, GOS and FOS have all been found to be effective in the management of constipation. GOS have been found to reduce the incidence of ‘traveller’s diarrhoea and FOS to reduce the severity of diarrhoea.

Administration of lactulose or oligofructose-enriched inulin has been found to reduce beta-glucuronidase activity (protective against colon cancer).

Lactulose has been shown to reduce incidence of urinary tract infections.

Inulin plus oligofructose has been shown to significantly improve calcium absorption in women. and promote satiety