The impact of bariatric surgery on macronutrient malabsorption depends on the type of procedure.

Introduction: Bariatric surgery, currently the most effective treatment for morbidly obese patients, may induce macronutrient malabsorption depending on the type of procedure. Macronutrient malabsorption affects the supply of substrates to the colon, subsequent microbial fermentation and possibly colonic health.

Methods: Using isotope technology, we quantified the extent of macronutrient and bile acid malabsorption and its impact on colonic protein fermentation in patients after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) and in controls.

CNCM I-3690 decreases subjective academic stress in healthy adults: a randomized placebo-controlled trial.

Psychological stress negatively affects the intestinal barrier function in animals and humans. We aimed to study the effect of CNCM I-3690 on intestinal permeability and stress-markers during public speech. Healthy students were randomized to -containing (test) or acidified (placebo) milk consumed twice daily for 4 weeks, with 46 subjects per treatment group.

Wheat bran with reduced particle size increases serum SCFAs in obese subjects without improving health parameters compared with a maltodextrin placebo.

Background: Wheat bran (WB) has been associated with improved gastrointestinal health and a reduced risk of metabolic disorders. Reducing the particle size of WB might increase its fermentability and facilitate cross-feeding between the gut bacteria and in this way produce health effects.

Objectives: We investigated the impact of WB with reduced particle size (WB RPS) on colonic fermentation and host health in normal-weight (NW) and obese (OB) participants compared with placebo (PL).

Wheat Bran Does Not Affect Postprandial Plasma Short-Chain Fatty Acids from C-inulin Fermentation in Healthy Subjects.

Wheat bran (WB) is a constituent of whole grain products with beneficial effects for human health. Within the human colon, such insoluble particles may be colonized by specific microbial teams which can stimulate cross-feeding, leading to a more efficient carbohydrate fermentation and an increased butyrate production. We investigated the extent to which WB fractions with different properties affect the fermentation of other carbohydrates in the colon.

Quantification of (15)N-nitrate in urine with gas chromatography combustion isotope ratio mass spectrometry to estimate endogenous NO production.

The use of stable isotope labeled substrates and subsequent analysis of urinary nitrate, forms a noninvasive test for evaluation of the in vivo NO metabolism. The present paper describes a new method for simultaneous quantification of (15)N-nitrate and total nitrate with gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS). Nitrate, isolated from urine with a nitrate selective resin, was reduced to nitrite using copperized cadmium.

Pouchitis, similar to active ulcerative colitis, is associated with impaired butyrate oxidation by intestinal mucosa.

Background: Healthy colonic mucosa uses butyrate as the major energy source. In ulcerative colitis (UC) butyrate oxidation has been shown to be disturbed, but it remains unclear whether this is a primary defect. The aim of this study was to measure mucosal butyrate oxidation in UC (involved and noninvolved colon) and in pouchitis and to study the relationship with endoscopic as well as histological disease activity.

Brassicaceae seed oil identified as illuminant in Nilotic shells from a first millennium AD Coptic church in Bawit, Egypt.

Burned greasy deposits were found inside shells of the large Nile bivalve Chambardia rubens, excavated in an eight- to tenth- century AD church of the Coptic monastery of Bawit, Egypt, and supposedly used as oil lamps. The residues were subjected to a combination of chromatographic residue analysis techniques. The rather high concentrations of unsaturated fatty acids, as analysed by gas chromatography (GC) in the methylated extract, suggest the presence of a vegetal oil.

The influence of inulin on the absorption of nitrogen and the production of metabolites of protein fermentation in the colon.

In the present study, the production and fate of bacterial metabolites in the colon were investigated in a direct way using two substrates labelled with stable isotopes: lactose [(15)N,(15)N]ureide as a source of labelled ammonia and egg proteins intrinsically labelled with [(2)H4]tyrosine as a precursor of [(2)H4]p-cresol. Both ammonia and phenolic compounds are believed to be carcinogenic. Stimulation of carbohydrate fermentation in order to prevent accumulation of these toxic metabolites was induced by inclusion of inulin in a test meal or by addition of inulin to the daily diet, allowing us to distinguish between changes induced by the actual presence of a fermentable carbohydrate and effects caused by a long-term dietary intervention.

Validation of lactose[15N,15N]ureide as a tool to study colonic nitrogen metabolism.

In vitro experiments have shown that fermentation of carbohydrates prevents accumulation of nitrogen in the colon. Variable results have been obtained on modulation of dietary intakes in vivo. Lactose[15N,15N]-labeled ureide has been proposed as a tool to study colonic nitrogen metabolism.

Validation of a new test meal for a protein digestion breath test in humans.

Previously, overall protein assimilation after the ingestion of a pure protein meal was studied. In this study, the kinetics of protein assimilation in humans were investigated after the ingestion of a complex meal, which more closely represents a physiologically normal situation. Overall protein assimilation in humans after the ingestion of a pancake meal, containing 12 g of fat, 27 g of carbohydrate, and 19 g of protein, was evaluated in 26 normal volunteers.