Modulation of the gut microbiota with antibiotic treatment suppresses whole body urea production in neonatal pigs

Abstract

We examined whether changes in the gut microbiota induced by clinically relevant interventions would impact the bioavailability of dietary amino acids in neonates. We tested the hypothesis that modulation of the gut microbiota in neonatal pigs receiving no treatment (control), intravenously administered antibiotics, or probiotics affects whole body nitrogen and amino acid turnover. We quantified whole body urea kinetics, threonine fluxes, and threonine disposal into protein, oxidation, and tissue protein synthesis with stable isotope techniques. Compared with controls, antibiotics reduced the number and diversity of bacterial species in the distal small intestine (SI) and colon. Antibiotics decreased plasma urea concentrations via decreased urea synthesis. Antibiotics elevated threonine plasma concentrations and turnover, as well as whole body protein synthesis and proteolysis. Antibiotics decreased protein synthesis rate in the proximal SI and liver but did not affect the distal SI, colon, or muscle. Probiotics induced a bifidogenic microbiota and decreased plasma urea concentrations but did not affect whole body threonine or protein metabolism. Probiotics decreased protein synthesis in the proximal SI but not in other tissues. In conclusion, modulation of the gut microbiota by antibiotics and probiotics reduced hepatic ureagenesis and intestinal protein synthesis, but neither altered whole body net threonine balance. These findings suggest that changes in amino acid and nitrogen metabolism resulting from antibiotic-or probiotic-induced shifts in the microbiota are localized to the gut and liver and have limited impact on whole body growth and anabolism in neonatal piglets.

Clinical chorioamnionitis at term I: microbiology of the amniotic cavity using cultivation and molecular techniques

“…Therefore, we conclude that a large fraction of patients with the diagnosis of clinical chorioamnionitis at term do not have bacterial infection. This has clinical implications, as all of these patients and their neonates receive antibiotics [113–120] which can change the neonatal microbiota [121–129] and may have long-term effects in their immune response [130, 131]. It is important to determine which patients require medical intervention, and this can be accomplished through characterization of the AF microbiology for a rational choice of antimicrobial therapy.…”

Disturbed intestinal nitrogen homeostasis in a mouse model of high-fat diet-induced obesity and glucose intolerance

“…Thus a decrease in CFU in both cecal and feces content would decrease AA catabolism and may improve the bioavailability of AAs. Indeed, modulation of the gut microbiota by antibiotic treatment increases plasma AA concentration in neonates compared with controls (45). However, so far, the relationships between HFD-induced modulations in gut microbiota and higher plasma AA concentrations remain unclear.…”

Muscle wasting: The gut microbiota as a new therapeutic target?

“…In addition, supplementation with Lactobacillus paracasei NCC2461 was associated with a specific fecal amino acid pattern in mice (Martin et al, 2010). Furthermore, the catabolism of dietary amino acids by the gut microbiota represents a net amino acid loss to the host (Puiman et al, 2013). Indeed, a 10-day intravenous antibiotics administration to neonatal piglets increased plasma levels of some amino acids but these changes were not accompanied by a net anabolic effect on whole body protein metabolism (Puiman et al, 2013).…”

“…Furthermore, the catabolism of dietary amino acids by the gut microbiota represents a net amino acid loss to the host (Puiman et al, 2013). Indeed, a 10-day intravenous antibiotics administration to neonatal piglets increased plasma levels of some amino acids but these changes were not accompanied by a net anabolic effect on whole body protein metabolism (Puiman et al, 2013). We cannot exclude that, in severe conditions such as undernutrition, gut microbial influence on amino acid bioavailability might become crucial, but this hypothesis requires further investigation.…”