In vitro faecal fermentation outcomes and microbiota shifts of resistant starch spherulites

Abstract

In the present study, we prepared A-and B-type polymorph-resistant starch spherulites (RSSs) with a wide range of crystallinity, and elucidated the relation between crystalline structure and faecal microbial fermentation outcomes. A-and B-type polymorphic RSSs displayed similar fermentation rate throughout entire process with final gas production of 11.8-13.2 mL, suggesting that the crystalline pattern and crystallinity cannot effectively control the fermentation rate of starches. The acetate and butyrate concentration of A-type RSS decreased with the increase of crystallinity respectively, and highly crystalline B-type RSS reduced the production of acetate (8.4 mM) and propionate (2.1 mM). RSSs with different crystalline types showed similar microbial community structure but distinct key bacteria species. A-type RSSs greatly promoted the abundance of butyrogenic bacteria (i.e., Roseburia faecis and Lachnospiraceae), whereas B-type RSSs tended to proliferate Prevotella copri associated with propionate production. Our findings shed new light on design and manufacture of starch-based functional ingredients with enhanced gut health.

Presence of digestible starch impacts in vitro fermentation of resistant starch

“…21,22 Although most of the digestible starch will be digested in the small intestine, still many studies discussing the fermentability of RS do not report the digestible fraction or remove this fraction prior to in vitro fermentation. 12,[23][24][25][26][27][28] Additionally, media used for in vitro fermentation, such as simulated ileal efflux medium (SIEM), routinely contain digestible starch. 29 The presence of a large fraction of digestible starch in the colon of healthy adults is only likely when acarbose is used to block pancreatic digestion 30 or originating from RS-1, in which otherwise digestible granules, such as present in wheat, rice or maize kernels, are protected by a cell-wall matrix and therefore not digested in the small intestine.…”

“…[38][39][40][41][42][43][44][45] Pre-digestion assays prior to in vitro fermentation have their weaknesses, such as inactivation of digestive enzymes without heat treatment, and drying of the obtained pre-digested fractions. Although some studies included digestible starch when studying in vitro fermentation of resistant starches, 12,[23][24][25][26][27][28] the impact of the presence of such a digestible starch fraction during in vitro fermentation by gut microbiota is not clarified in detail yet.…”

Human health‐promoting interactions between hydrocolloid‐structured foods and the gut microbiome in the digestive tract: Editorial

“…It is noteworthy that the amount and proportion of metabolites as well as the microbial responses to dietary fibre are highly structure dependent, even though they behave quite differently within the same resistant starch category (Hamaker & Tuncil, 2014;Tuncil et al, 2020). In particular, there are five papers in this special issue, which deserve attention, the first paper entitled as in vitro fecal fermentation outcomes and microbiota shifts of resistant starch spherulites by Liu et al (2021b). It demonstrated that after in vitro colonic fermentation, the B-type of retrograded starches showed higher butyrate production and remarkably increased the number of Bifidobacterium species, whereas the A-type of polymorph promoted the growth of Atopobium and Bacteroides species (Lesmes et al, 2008).…”

“…The trillions of human large intestine bacteria form a complex microbial community known as the gut microbiota, which plays an important role in the host's metabolism and immune system (Makki et al ., 2018; Liu et al ., 2021b). The individual response of gut microbiota to different diets is a significant determinant in shaping the microbial community.…”

“…In particular, there are five papers in this special issue, which deserve attention, the first paper entitled as in vitro fecal fermentation outcomes and microbiota shifts of resistant starch spherulites by Liu et al . (2021b). It demonstrated that after in vitro colonic fermentation, the B‐type of retrograded starches showed higher butyrate production and remarkably increased the number of Bifidobacterium species, whereas the A‐type of polymorph promoted the growth of Atopobium and Bacteroides species (Lesmes et al ., 2008).…”