Researchers from the University of Reading in the UK and the Mexican firm Bustar Alimentos – which markets inulin, oligofructose and agave sweeteners – looked at the impact of three-week supplementation of 5 grams of agave fructan per day compared to an equivalent placebo of the fibre maltodextrin.
The 38 adults then went through a two-week ‘washout’ period before swapping treatment groups for another three weeks then going through a final two-week 'washout'.
At each stage faecal samples were taken and changes in faecal bacterial populations, short-chain fatty acids and the antibody immunoglobulin A (IgA) were tracked as was the effect of agave on different regions of the colon. Using a daily questionnaire they also recorded bowel movements, stool consistencies, abdominal comfort and any mood changes.
The results, published in Journal of Nutritional Science, revealed that faecal counts of bifidobacteria and lactobacilli were significantly increased when compared to the placebo. However, no difference was seen between the two groups for other strains or for the other aspects examined.
Increased bloating and flatulence
Quality of life factors like mood, alertness, energy and stress levels were not impacted by agave supplementation. However they said effects on bowel habits were “more profound” – with no significant changes in stool frequency or consistency or abdominal pain observed but a significantly increased rate of intestinal bloating (mild to moderate) and flatulence (mild and severe) recorded by the agave subjects.
They concluded that agave was well tolerated in healthy human subject.
“In conclusion, in vivo and in vitro data confirm the prebiotic effectiveness of agave fructans as observed by selective increases in bifidobacteria and lactobacilli populations. Agave represents an important alternative prebiotic to other sources of fructans.”
They said its good solubility in cold water meant that it could be easily incorporated into beverages, dairy products, cheese and yoghurt.
The participants were given either the agave or maltodextrin in powdered form in blind-tested blank packaging. The agave used was Predilife, a purified powder extracted from Agave tequilana, while the maltodextrin was a commercially available product produced by Tate and Lyle.
The researchers said this was the first trial of its kind to looks at these factors.
Source: Journal of Nutritional Science
Vol. 4, iss. 10, pp 1-10, doi:10.1017/jns.2014.68
“A randomised, double- blind, cross-over study investigating the prebiotic effect of agave fructans in healthy human subjects”
Authors: P. Ramnani, A. Costabile, A. G. R. Bustillo and G. R. Gibson