Biology subjects

Van Camp, J.

Publications and source records attributed to Van Camp, J..

3 recordsLinked to original sources

bioRxiv2021

Long term exposure of human gut microbiota with high and low emulsifier sensitivity to soy lecithin in M-SHIME model.

In the context of the potential health hazards related to food processing, dietary emulsifiers have been shown to alter the structure and function of the gut microbial community, both in vivo and in vitro. In mouse models, these emulsifier exposed gut microbiota were shown to contribute to gut inflammation. Several knowledge gaps remain to be addressed though. As such, the impact from a longer timeframe of exposure on the gut microbiota is not known and interindividual variability in microbiome response needs to be measured. To answer these research questions, in this study the faecal microbiota from two individuals, previously selected for high and low emulsifier sensitivity, were exposed to two concentrations of soy lecithin during a 7 day treatment phase in the dynamic mucosal simulator of the human intestinal microbial ecosystem (M-SHIME). The results showed mild effects from soy lecithin on the composition and functionality of these microbial communities, which depended on the original microbial composition. The effects also mostly levelled off after 3 days of exposure. The emulsifier sensitivity for which the microbiota were selected, was preserved. Some potentially concerning effects were also registered: butyrate levels, positively correlating with Faecalibacterium abundance, were lowered by soy lecithin. Also the abundance of the beneficial Bifidobacterium genus was lowered, while the abundance of the notorious unclassified Enterobacteriaceae was increased. Within the family of the unclassified Lachnospiraceae, several genera were either suppressed or stimulated. The effects that these microbial alterations would have on a living host is not yet certain, especially given the fact that large fractions of soy lecithins constituents can be absorbed. Nevertheless, choline and phosphatidylcholine, both primary and absorbable constituents of soy lecithin, have recently been linked to cardiovascular disease via the generation of TMA by the gut microbiota. Further studies that validate our findings and link them to potential health outcomes are thus justified.

microbiology↗

bioRxiv2021

Differential impact of rhamnolipids and polysorbate80 on composition and functionality of the gut microbiota in the SHIME system.

Dietary emulsifiers have been shown to affect the composition and function of the gut microbial community, both in vivo and in vitro. Yet, several knowledge gaps remain to be addressed: the impact from a longer timeframe exposure on the gut microbiota, interindividual variability in microbiome response and the putative impact from novel clean label alternatives for current food emulsifiers. In the present study, the impact of one conventional dietary emulsifier, TWEEN80, and one potential novel alternative, rhamnolipids, on the human gut microbiota was investigated using the Mucosal Simulator of the Human Intestinal Microbial Ecosystem (M-SHIME). The faecal microbiota from two human donors, with high and low responsiveness to the emulsifiers, were exposed to 0,05 m% and 0,5 m% of the emulsifiers for 7 days. The results confirmed previous observations that the effects on the composition and functionality are both emulsifier- and donor dependent. The effects reached an equilibrium after about 3 days of exposure. Overall, TWEEN80 and rhamnolipids displayed opposite effects: TWEEN80 increased cell counts, reduced propionate concentration, increased butyrate levels, increased a.o. Faecalibacterium, Blautia and Hungatella abundance, while rhamnolipids did the opposite. Rhamnolipids also sharply increased the abundance of unclassified Lachnospiraceae. On the other hand, both emulsifiers increased the relative abundance of unclassified Enterobacteriaceae. Both emulsifiers also altered the microbial metabolome in different ways and a pathway enrichment analysis tool revealed that the metabolome alterations could be reminiscent of gut issues and obesity. Overall, the impact from the rhamnolipids was larger than that of TWEEN80 at similar concentrations, indicating that the former may not necessarily be a safer alternative for the latter. The microbiotas response also depended on its original composition and the sensitivity status for which the faecal donors were selected, was preserved. Whether the same donor-diversity and longitudinal impact can be expected in the human colon as well and what impact this has on the host will have to be further investigated.

microbiology↗

bioRxiv2020

Dietary emulsifiers alter composition and activity of the human gut microbiota in vitro, irrespective of chemical or natural emulsifier origin.

The use of additives in food products has become an important public health concern. In recent reports, dietary emulsifiers have been shown to affect the gut microbiota, contributing to a pro-inflammatory phenotype and metabolic syndrome. So far, it is not yet known whether similar microbiome shifts are observable for a more diverse set of emulsifier types and to what extent these effects vary with the unique features of an individuals microbiome. To bridge this gap, we investigated the effect of five dietary emulsifiers on the fecal microbiota from 10 human individuals upon a 48 hour exposure. Community structure was assessed with quantative microbial profiling, functionality was evaluated by measuring fermentation metabolites and pro-inflammatory properties were assessed with the phylogenetic prediction algorythm PICRUSt, together with a TLR5 reporter cell assay for flagellin. A comparison was made between two mainstream chemical emulsifiers (carboxymethylcellulose and P80), a natural extract (soy lecithin) and biotechnological emulsifiers (sophorolipids and rhamnolipids). While fecal microbiota responded in a donor-dependent manner to the different emulsifiers, profound differences between emulsifier were observed. Rhamnolipids, sophorolipids and soy lecithin eliminated 91% {+/-} 0%, 89% {+/-} 1% and 87% {+/-} 1% of the viable bacterial population after 48 hours, yet they all selectively increased the proportional abundance of putative pathogens. Moreover, profound shifts in butyrate (-96% {+/-} 6 %, -73% {+/-} 24% and -34 {+/-} 25% respectively) and propionate (+13% {+/-} 24 %, +88% {+/-} 50% and +29% {+/-} 16% respectively) production were observed for these emulsifiers. Phylogenetic prediction indicated higher motility, which was, however, not confirmed by increased flagellin levels using the TLR5 reporter cell assay. We conclude that dietary emulsifiers can severely impact the gut microbiota and this seems to be proportional to their emulsifying strength, rather than emulsifier type or origin. As biotechnological emulsifiers were especially more impactful than chemical emulsifiers, caution is warranted when considering them as more natural alternatives for clean label strategies.

microbiology↗