In vitro Utilization of Gold and Green Kiwifruit Oligosaccharides by Human Gut Microbial Populations

Abstract

We examined the effects of whole kiwifruit on gut microbiota using an in vitro batch model of gastric-ileal digestion and colonic fermentation. Faecal fermentations of gold and green kiwifruit, inulin and water (control) digests were performed for up to 48 h. As compared to the control, gold and green kiwifruit increased Bifidobacterium spp. by 0.9 and 0.8 log(10) cfu/ml, respectively (P < 0.001), and the Bacteroides-Prevotella-Porphyromonas group by 0.4 and 0.5 log(10) cfu/ml, respectively. Inulin only had a bifidogenic effect (+0.4 log(10) cfu/ml). This was accompanied with increases in microbial glycosidases, especially those with substrate specificities relating to the breakdown of kiwifruit oligosaccharides, and with increased generation of short chain fatty acids. The microbial metabolic activity was sustained for up to 48 h, which we attribute to the complexity of the carbohydrate substrate provided by whole kiwifruit. Kiwifruit fermenta supernatant was also separately shown to affect the in vitro proliferation of Bifidobacterium longum, and its adhesion to Caco-2 intestinal epithelial cells. Collectively, these data suggest that whole kiwifruit may modulate human gut microbial composition and metabolism to produce metabolites conducive to increased bifidobacteria-host association.

Influence of Green and Gold Kiwifruit on Indices of Large Bowel Function in Healthy Rats

“…Butyric acid levels tended to be higher in rats fed green kiwifruit compared to control ( P = 0.062 for the diet effect; Figure B). This finding is consistent with our previous in vitro study that showed utilization of green kiwifruit by gut microbial populations enhanced the production of SCFAs (acetic, butyric, and propionic acids; Parkar and others ). In comparison to the control diet group, rats fed green kiwifruit had lower propionic acid concentrations at week 4, although this tended to increase at week 6 ( P = 0.098 for the diet × week interaction).…”

“…The benefit of consuming whole kiwifruit for promoting the development of GI health is an emerging research area. In a recent study using the in vitro batch culture model of gastric–ileal digestion and colonic fermentation, we demonstrated the positive effects of green and gold kiwifruit on human gut microbial populations, specifically increasing the growth of Bifidobacterium and Lactobacillus species and promoting butyrate levels (Parkar and others ). These in vitro changes in microbiota metabolism suggest that kiwifruit consumption could positively influence mucosal cell development within the large bowel in vivo .…”

Evaluation of the prebiotic potential of five kiwifruit cultivars after simulated gastrointestinal digestion and fermentation with human faecal bacteria

“…Briefly, the kiwifruit were incubated with pepsin (pH 2.0), and then amyloglucosidase plus pancreatin (pH 6.0) and then dialysed with a 10 kDa molecular weight cut-off membrane to simulate intestinal absorption. The final substrate concentrations for the kiwifruit samples, equivalent to a fresh weight of 25 g% (w/v), were calculated to be potentially achieved on consuming two kiwifruit of an average size of 100 g (Parkar et al, 2012). for 16 h. The fermenta were then collected as 2 9 1 mL aliquots and stored at À80°C for the analysis of microbial abundance and acid metabolites.…”

In vitro prebiotic activities of tamarillo (Solanum betaceum Cav.) hydrocolloids

“…Besides that, oligosaccharides from apple and citrus pectin hydrolysates (Olano-Martin, Gibson, & Rastall, 2002), kiwifruit (Parkar et al, 2012), dragon fruit (Wichienchot, Jatupornpipat, & Rastall, 2010) and low molecular weight polysaccharides derived from agar and alginate (Ramnani et al, 2012) were also reported to demonstrate good prebiotic activities. The low molecular weight tamarillo seed mucilage hydrocolloid may demonstrate better prebiotic activity than the high molecular weight pulp hydrocolloid.…”