Probiotics in gnotobiotic mice: Short-chain fatty acids production in vitro and in vivo

Several bacterial strains are currently used as probioties. Sixteen of them belonging to the genera: Bifidobacterium. Enterococcus. Lactobacillus and Streptococcus, were selected to test short-ehain fatty acids (StJFAs) production in w‘tm and/‘er in viva. The probiotic strains were monoeultivated in specific media and/or monoassoeiated with NMRl-Kl germfree (GF) mice. The individual and total amounts of SCFAs were measured in the media and in the large intestinal content of the ex-GF mice. All the samples were assayed by gas-liquid chromatography. We found that commercially available media contain detectable amounts of acetic and propionic acids. When cultivated in vitro. none of the probiotie strains was able to increase the amounts of SCFAS present in the medium. Rather, a tendency to lowering the concentration of SCFAs following cultivation. was observed. We also found that commercially available laboratory rodents chow contained detectable amount of all SCFAs. When the probiotics were monoinoculated t0 GF animals, nine out of sixteen groups of mice showed higher amount of intestinal SCFAS than in the GF control group. Acetic acid was the dominant one. In all eases. however, the values of the SCFAs were far from those found in conventional mice.The results clearly underline the importance of working with laboratory animals with a known flora. i. e. gnotobiotie animals, when the biochemical “profile" eta prohiotie is worked out

Intestinal fermentation in patients with self-reported food hypersensitivity: painful, but protective?

Purpose: Enterometabolic disturbances may cause meal-related symptoms. We performed a functional evaluation of the intestinal microflora in patients with unexplained, self-reported food hypersensitivity by measuring fecal short-chain fatty acids (SCFAs). Patients and methods: Thirty-five consecutive patients with self-reported food hypersensitivity and 15 healthy volunteers of similar age, gender, and body mass index collected all feces for 72 hours. Fecal concentrations of acetic, propionic, n-butyric, i-butyric, n-valeric, i-valeric, n-caproic, and i-caproic acids were analyzed by gas-liquid chromatography. Concentrations and excretions (output) of SCFAs in patients and controls were compared and related to gastrointestinal symptoms. Results: Despite nonsignificant differences between patients and controls for both total and individual SCFA concentrations and excretions, n-butyric acid comprised a higher (P = 0.035) and acetic acid a lower (P = 0.012) proportion of total SCFA in patients compared to controls. There were no significant correlations between symptom scores and concentrations or excretions of individual or total SCFAs, but the proportion of n-butyric acid was significantly higher in patients with severe symptoms compared to patients with moderate symptoms (P = 0.016). Conclusion: The results indicate an enterometabolic disturbance in patients with self-reported food hypersensitivity. Higher proportions of n-butyric acid may be related to abdominal symptom generation, but may also protect against organic bowel disease. Further studies are needed to clarify these aspects

Probiotic Biotherapy for Eradication of a Potential Pathogen in a Commercial Rat Breeding Facility

This study defined a model for biotherapeutic eradication of beta-haemolytic streptococci, group G, in a rat  breeding unit (3100 rats) by use of a strain of Lactobacillus reuteri. The microbe was added to the rats’  drinking water and the genitals of all rats were swabbed three times with a solution of the microbe. After this  procedure undesirable streptococci were not recognized in any animal of this breeding farm.

Environmental toxicants in breast milk of Norwegian mothers and gut bacteria composition and metabolites in their infants at 1 month.

BACKGROUND:Early disruption of the microbial community may influence life-long health. Environmental toxicants can contaminate breast milk and the developing infant gut microbiome is directly exposed. We investigated whether environmental toxicants in breastmilk affect the composition and function of the infant gut microbiome at 1 month. We measured environmental toxicants in breastmilk, fecal short-chain fatty acids (SCFAs), and gut microbial composition from 16S rRNA gene amplicon sequencing using samples from 267 mother-child pairs in the Norwegian Microbiota Cohort (NoMIC). We tested 28 chemical exposures: polychlorinated biphenyls (PCBs), polybrominated flame retardants (PBDEs), per- and polyfluoroalkyl substances (PFASs), and organochlorine pesticides. We assessed chemical exposure and alpha diversity/SCFAs using elastic net regression modeling and generalized linear models, adjusting for confounders, and variation in beta diversity (UniFrac), taxa abundance (ANCOM), and predicted metagenomes (PiCRUSt) in low, medium, and high exposed groups. RESULTS:PBDE-28 and the surfactant perfluorooctanesulfonic acid (PFOS) were associated with less microbiome diversity. Some sub-OTUs of Lactobacillus, an important genus in early life, were lower in abundance in samples from infants with relative "high" (> 80th percentile) vs. "low" (< 20th percentile) toxicant exposure in this cohort. Moreover, breast milk toxicants were associated with microbiome functionality, explaining up to 34% of variance in acetic and propionic SCFAs, essential signaling molecules. Per one standard deviation of exposure, PBDE-28 was associated with less propionic acid (- 24% [95% CI - 35% to - 14%] relative to the mean), and PCB-209 with less acetic acid (- 15% [95% CI - 29% to - 0.4%]). Conversely, PFOA and dioxin-like PCB-167 were associated with 61% (95% CI 35% to 87%) and 22% (95% CI 8% to 35%) more propionic and acetic acid, respectively. CONCLUSIONS:Environmental toxicant exposure may influence infant gut microbial function during a critical developmental window. Future studies are needed to replicate these novel findings and investigate whether this has any impact on child health

Environmental toxicants in breast milk of Norwegian mothers and gut bacteria composition and metabolites in their infants at 1 month

Iszatt N, Janssen S, Lenters V, et al. Environmental toxicants in breast milk of Norwegian mothers and gut bacteria composition and metabolites in their infants at 1 month. Microbiome. 2019;7(1): 34

Assessment of benefits and risks of probiotics in processed cereal-based baby foods Lactobacillus paracasei ssp. paracasei F19

Source at https://vkm.no/The Norwegian Scientific Committee for Food Safety (VKM) has appointed an ad hoc-group of experts to answer a request from the Norwegian Food Safety Authority regarding benefit and risk assessment of Lactobacillus paracasei ssp. paracasei F19 (F19) in processed cereal-based baby foods intended for small children 1-3 years. This assessment is based on the literature provided by the notifier as well as that found by a MEDLINE search.Vitenskapskomiteen for mattrygghet (VKM) har på oppdrag fra Mattilsynet utarbeidet en nytte- og risikovurdering av Lactobacillus paracasei ssp. paracasei F19 (F19) tilsatt i barnegrøt til barn i alderen 1-3 år. For å besvare oppdraget nedsatte VKM en ad hoc-gruppe. Vurderingen er basert på gjennomgang av litteratur tilsendt fra virksomheten og MEDLINE litteratursøk

Novel Developmental Analyses Identify Longitudinal Patterns of Early Gut Microbiota that Affect Infant Growth

It is acknowledged that some obesity trajectories are set early in life, and that rapid weight gain in infancy is a risk factor for later development of obesity. Identifying modifiable factors associated with early rapid weight gain is a prerequisite for curtailing the growing worldwide obesity epidemic. Recently, much attention has been given to findings indicating that gut microbiota may play a role in obesity development. We aim at identifying how the development of early gut microbiota is associated with expected infant growth. We developed a novel procedure that allows for the identification of longitudinal gut microbiota patterns (corresponding to the gut ecosystem developing), which are associated with an outcome of interest, while appropriately controlling for the false discovery rate. Our method identified developmental pathways of Staphylococcus species and Escherichia coli that were associated with expected growth, and traditional methods indicated that the detection of Bacteroides species at day 30 was associated with growth. Our method should have wide future applicability for studying gut microbiota, and is particularly important for translational considerations, as it is critical to understand the timing of microbiome transitions prior to attempting to manipulate gut microbiota in early life