Probiotic or synbiotic alters the gut microbiota and metabolism in a randomised controlled trial of weight management in overweight adults

The gut microbiota contributes to host energy metabolism, and altered gut microbiota has been associated with obesity-related metabolic disorders. We previously reported that a probiotic alone or together with a prebiotic controls body fat mass in healthy overweight or obese individuals in a randomised, double-blind, placebo controlled clinical study (ClinicalTrials.gov NCT01978691). We now aimed to investigate whether changes in the gut microbiota may be associated with the observed clinical benefits. Faecal and plasma samples were obtained from a protocol compliant subset (n=134) of participants from a larger clinical study where participants were randomised (1:1:1:1) into four groups: (1) placebo, 12 g/d microcrystalline cellulose; (2) Litesse® Ultra™ polydextrose (LU), 12 g/day; (3) Bifidobacterium animalis subsp. lactis 420™ (B420), 10¹⁰ cfu/d in 12 g microcrystalline cellulose; (4) LU+B420, 1010 cfu/d of B420 in 12 g/d LU for 6 months of intervention. The faecal microbiota composition and metabolites were assessed as exploratory outcomes at baseline, 2, 4, 6 months, and +1 month post-intervention and correlated to obesity-related clinical outcomes. Lactobacillus and Akkermansia were more abundant with B420 at the end of the intervention. LU+B420 increased Akkermansia, Christensenellaceae and Methanobrevibacter, while Paraprevotella was reduced. Christensenellaceae was consistently increased in the LU and LU+B420 groups across the intervention time points, and correlated negatively to waist-hip ratio and energy intake at baseline, and waist-area body fat mass after 6 months treatment with LU+B420. Functional metagenome predictions indicated alterations in pathways related to cellular processes and metabolism. Plasma bile acids glycocholic acid, glycoursodeoxycholic acid, and taurohyodeoxycholic acid and tauroursodeoxycholic acid were reduced in LU+B420 compared to Placebo. Consumption of B420 and its combination with LU resulted in alterations of the gut microbiota and its metabolism, and may support improved gut barrier function and obesity-related markers.

Effect of probiotic supplementation on total lactobacilli, bifidobacteria and short chain fatty acids in 2-5-year-old children

​Background: Consumption of Lactobacillus paracasei Lpc-37 or Bifidobacterium lactis HN019 by 2-5-year-old children was found to reduce risk for diarrhoea and fever during the rainy season. Objective: Can changes in faecal short chain fatty acids (SCFAs) or branched chain fatty acids (BCFAs) explain the observed positive influence of probiotics and their role on nutritional status and diarrhoea risk? Design: Faecal samples were analysed for SCFAs and BCFAs and correlated to Bifidobacterium and Lactobacillus levels; both at the start and after nine months' consumption of either of the two probiotic strains, or placebo. Results: No differences in SCFAs, BCFAs, Lactobacillus or Bifidobacterium levels were found between boys and girls. Severely underweight children were observed to have the highest Lactobacillus levels. Probiotic intervention was found to be associated with higher levels of selected SCFAs and BCFAs in subjects who had experienced diarrhoea. Treatment with either of the probiotics led to changes in SCFAs and BCFAs. SCFAs, acetate, propionate and butyrate, were found to correlate with each other. Likewise, BCFAs isobutyrate, 2-methylbutyrate and isovalerate correlated with each other. After the intervention, L. paracasei Lpc-37 correlated positively with total Bifidobacterium counts and isovalerate levels. B. lactis HN019 counts were found to correlate positively with total bacterial counts and negatively with propionate levels. Conclusions: ​Nutritional status was associated with higher levels of faecal lactobacilli; the meaning of this requires further investigation. The intervention with the two probiotics was observed to influence the levels of faecal SCFAs and BCFAs and there is a differential response in those who developed diarrhoea and those who did not. It is, however, not clear to what extent this is a mechanism that explains the earlier observed effect the strains had on diarrhoea risk.

Dietary betaine accumulates in the liver and intestinal tissue and stabilizes the intestinal epithelial structure in healthy and coccidia-infected broiler chicks

The aim of this experiment was to study the patterns of betaine accumulation into intestinal tissue, liver and plasma of broiler chicks with or without coccidial infection. The chicks were raised on a corn-based, low-betaine diet with or without 1000 ppm betaine supplementation and with or without intestinal microparasite (Eimeria maxima) challenge to the age of 21 days. Plasma, liver, intestinal tissue and digesta of non-challenged (NC) birds and plasma and intestinal tissue of coccidiosis challenged (CC) birds were analysed for betaine content. NC birds were also analyzed for homocysteine in plasma and S-adenosylmethionine (S-AM) in liver. The jejunal epithelium was histologically examined for the presence of coccidia and the crypt-villus ratio was measured. Dietary betaine supplementation decreased the plasma homocysteine concentration but had no effect on liver S-AM of NC birds. The data suggest that chicks on a low-betaine diet accumulate betaine into the intestinal tissue. When the diet was supplemented with betaine, betaine accumulated heavily into liver and to a lesser degree into intestinal tissue. The concentration of betaine in jejunal and ileal digesta was low suggesting that dietary betaine was mainly absorbed from the proximal small intestine. The coccidial challenge decreased the concentration of betaine in the liver, but greatly increased that in the intestinal tissue. The crypt-villus ratio was decreased by the dietary betaine supplementation in healthy and challenged chicks, suggesting that dietary betaine both protects the jejunal villi against coccidial infection and also stabilizes the mucosal structure in healthy broiler chicks. These results support our earlier findings suggesting that betaine is likely to act as an important intestinal osmolyte in broiler chicks.

A novel method to analyze betaine in chicken liver: effect of dietary betaine and choline supplementation on the hepatic betaine concentration in broiler chicks

Betaine was measured from liver tissue by a high-performance liquid chromatographic (HPLC) method developed for this study. The method involves homogenization of liver in acetate buffer at pH 6 and precipitation of protein with trichloroacetic acid, which was removed by diethyl ether extraction. Betaine was separated using a cation exchange column in Ca(2+) form and detected with a refractive index detector. This method also allows the determination of S-adenosylmethionine (S-AM) from the same liver extract but with different HPLC conditions. Broiler chicks were fed with experimental diets supplemented with four different doses of betaine or choline ranging from 0 to 5 mol equiv. After a 3 week feeding period, the livers were analyzed for betaine and S-AM. Dietary betaine was twice as efficient in increasing the hepatic betaine concentration as dietary choline. The hepatic S-AM concentrations were similar in all dietary treatments.

Screening and determination of beta-blockers, narcotic analgesics and stimulants in urine by high-performance liquid chromatography with column switching

A fast method is described for the screening of eleven beta-blockers, two narcotic analgesics and two stimulants in urine by HPLC with column switching. The urine sample (100 microliters), buffered to pH 9-9.5, is injected onto a short extraction column packed with CN stationary phase. The extraction column is flushed with water for 2.5 min to elute polar matrix components to waste. The retained components are then backflushed by means of a six-port valve onto the ODS analytical column where they are separated. Phosphate buffer pH 3.0 and acetonitrile were used as mobile phase. Gradient elution was applied in the screening method to improve separation. Detection was performed with a diode-array detector at 220, 235 and 300 nm. Recoveries were near 100%, precision was excellent and sensitivity about 0.25 micrograms/l. To speed up the quantitative analysis, the same method but with isocratic elution was successfully applied to the determination of acebutolol and metoprolol in urine samples collected 4 h after administration of the compounds as single doses.