Microbial Translocation and Perinatal Asphyxia/Hypoxia: A Systematic Review

The microbiome is vital for the proper function of the gastrointestinal tract (GIT) and the maintenance of overall wellbeing. Gut ischemia may lead to disruption of the intestinal mucosal barrier, resulting in bacterial translocation. In this systematic review, according to PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines, we constructed a search query using the PICOT (Patient, Intervention, Comparison, Outcome, Time) framework. Eligible studies reported in PubMed, up to April 2021 were selected, from which, 57 publications’ data were included. According to these, escape of intraluminal potentially harmful factors into the systemic circulation and their transmission to distant organs and tissues, in utero, at birth, or immediately after, can be caused by reduced blood oxygenation. Various factors are involved in this situation. The GIT is a target organ, with high sensitivity to ischemia–hypoxia, and even short periods of ischemia may cause significant local tissue damage. Fetal hypoxia and perinatal asphyxia reduce bowel motility, especially in preterm neonates. Despite the fact that microbiome arouse the interest of scientists in recent decades, the pathophysiologic patterns which mediate in perinatal hypoxia/asphyxia conditions and gut function have not yet been well understood.

Centenarian-Sourced Lactobacillus casei Combined with Dietary Fiber Complex Ameliorates Brain and Gut Function in Aged Mice

Dietary intervention could modulate age-related neurological disorders via the gut–brain axis. The potential roles of a probiotic and the dietary fiber complex (DFC) on brain and gut function in aged mice were investigated in this study. Lactobacillus casei LTL1361 and DFC were orally administrated for 12 weeks, and the learning and memory ability, as well as the oxidative parameters, inflammatory markers, gut barrier function and microbial metabolite short-chain fatty acids (SCFAs), were investigated. LTL1361 and DFC supplementation ameliorated cognitive ability, attenuated oxidative stress in brain and inflammation in serum and colon, ameliorated gut barrier function, and increased the SCFA concentrations and gene expression of SCFA receptors. The protective effect was more significantly enhanced in aged mice treated with the combination of LTL1361 and DFC than treated with LTL1361 or DFC alone. These results could be associated with the protected morphology of pyramidal nerve cells in hippocampus of mice brain and the downregulation of apoptosis marker caspase-3 in brain and upregulation of tight junction proteins in small intestine and colon. The results indicated that Lactobacillus casei LTL1361 and DFC alleviated age-related cognitive impairment, as well as protected brain and gut function. Lactobacillus casei LTL1361 and DFC might be used as novel and promising antiaging agents in human.

The use of exogenous enzymes to optimize gut function in pigs

Exogenous enzymes are used in pig diets to improve the availability and digestibility of some non-accessible nutrients. As result of this enhanced digestion, short fragments of these molecules may become available in the distal foregut and the hindgut and modulate microbiota composition, gut barrier integrity, and overall animal health. This chapter reviews the effects of different exogenous enzymes (carbohydrases, phytases, proteases and lipases) on nutrient digestibility, gut microbial ecology, and barrier function and immunity of pigs at different ages (sows, weaned piglets, growing/fattening pigs). Exogenous enzymes are usually included into feeds as blends so they can complement each other’s activities and further improve the accessibility to non-digestible structures. Exogenous enzymes used in feed manufacturing for more than 30 years, initially to improve the digestive function of non-digestible nutrients (i.e. fibre, phytic acid, etc.), more recently other indirect actions on the regulation of gut microbiota and gut health have gained interest.

Improving gut function in pigs to prevent dysbiosis and post-weaning diarrhoea

Post-weaning diarrhoea (PWD) is a significant enteric disease causing considerable economic losses for the pig industry. There are multiple factors for why pigs develop diarrhea post-weaning and require treatment with antibiotics. The condition ‘dysbiosis’ can be considered as an ecosystem where bacteria no longer live together in mutual harmony. With regard to development of PWD, we therefore consider this as a process in a simplistic manner, i.e., dysbiosis appears when the commensal no longer control the potential pathogenic bacteria. When the pathogenic bacteria colonize and adhere to the epithelium of the gut, they may induce diarrhea. There are a number of factors by which the gut function can be improved, and prevention of dysbiosis exert a major role herein. The objective is to provide an overview of factors, which may enhance gut function both in terms of a balanced or eubiotic ecosystem, and with regard to the epithelial barrier function.

The use of dietary fibre to optimize microbial gut function in pigs, with particular consideration of dietary cereal grains and legumes

This chapter examines interactions of dietary fibre components of pig diets with GIT microbiota, emphasizing cereals and legumes fed to pigs. Carbohydrate composition of these feedstuffs are described, and their relationship to metabolic activity of the porcine intestinal microbiota and interactions with the host. Fermentable carbohydrates which act as substrates for microbial metabolism are described, followed by an assessment of cereals and legumes as potential modulators of intestinal microbiota. Past work focussed on purified extracts, but attention is now focussing on whole grains or their fractions such as brans, in terms of effects on microbial populations. Such studies are showing the positive consequences of mixtures of DF in the form of complex plant cellular structures, rather than single refined ingredients, to achieve beneficial health outcomes. Further work is also needed to define appropriate quantities and types of DF to achieve desired effects whilst minimising negative outcomes.

The use of prebiotics to optimize gut function in pigs

Colonization of the porcine gut microbiota commences after birth; however, this development is interrupted at weaning, rendering the piglet vulnerable to enteric disease. Dietary supplementation of non-digestible oligosaccharides can contribute to the stabilization of gut homeostasis by promotion of saccharolytic bacteria, inhibition of opportunistic pathogens, bacterial metabolite production and immune regulation. Whilst traditionally fructans and galactooligosaccharides have been added to weaner pig diets, supplementation of sow’s gestation and lactation diets and oral administration of suckling piglets may exert some beneficial effects too to promote gut microbiota and (immune) function development. Oligosaccharides in sow milk act as prebiotics by specifically shaping the gut microbiota of the offspring. This chapter summarizes the current knowledge on effects of prebiotic oligosaccharides on porcine gut function and health. The modes of actions of those substances are discussed as well as aspects that need more investigation for future applications in diets for suckling piglets.

Phytogenic Feed Additives in Poultry: Achievements, Prospective and Challenges

Phytogenic feed additives have been largely tested in poultry production with the aim to identify their effects on the gastrointestinal function and health, and their implications on the birds’ systemic health and welfare, the production efficiency of flocks, food safety, and environmental impact. These feed additives originating from plants, and consisting of herbs, spices, fruit, and other plant parts, include many different bioactive ingredients. Reviewing published documents about the supplementation of phytogenic feed additives reveals contradictory results regarding their effectiveness in poultry production. This indicates that more effort is still needed to determine the appropriate inclusion levels and fully elucidate their mode of actions. In this frame, this review aimed to sum up the current trends in the use of phytogenic feed additives in poultry with a special focus on their interaction with gut ecosystem, gut function, in vivo oxidative status and immune system as well as other feed additives, especially organic acids.

Sport supplements and the athlete’s gut: a review.

Vigorous or prolonged exercise poses a challenge to gastrointestinal system functioning and is associated with digestive symptoms. This narrative review addresses 1) the potential of dietary supplements to enhance gut function and reduce exercise-associated gastrointestinal symptoms and 2) strategies for reducing gastrointestinal-related side effects resulting from popular sports supplements. Several supplements, including probiotics, glutamine, and bovine colostrum, have been shown to reduce markers of gastrointestinal damage and permeability with exercise. Yet, the clinical ramifications of these findings are uncertain, as improvements in symptoms have not been consistently observed. Among these supplements, probiotics modestly reduced exercise-associated gastrointestinal symptoms in a few studies, suggesting they are the most evidenced-based choice for athletes looking to manage such symptoms through supplementation. Carbohydrate, caffeine, and sodium bicarbonate are evidence-based supplements that can trigger gastrointestinal symptoms. Using glucose-fructose mixtures is beneficial when carbohydrate ingestion is high (>50 g/h) during exercise, and undertaking multiple gut training sessions prior to competition may also be helpful. Approaches for preventing caffeine-induced gastrointestinal disturbances include using low-to-moderate doses (<500 mg) and avoiding/minimizing exacerbating factors (stress, anxiety, other stimulants, fasting). Adverse gastrointestinal effects of sodium bicarbonate can be avoided by using enteric-coated formulations, low doses (0.2 g/kg), or multi-day loading protocols.

Use of low dosage amino acid blends to prevent stress-related piglet diarrhea

Weaning is a challenging period for piglets associated with reduced feed intake, impairment of gut integrity, and diarrhea. Previous studies demonstrate that supplementation with single functional amino acids promote piglets’ performance due to the improvement of intestinal health. Thus, we hypothesized that a combination of functional amino acids provided beyond the postulated requirement for growth could facilitate the weaning transition. Ninety piglets, initially stressed after weaning by 100 min overland transport, received a control diet or the same diet supplemented with a low-dosed (0.3 %) mixture of amino acids (AAB-1: L-arginine, L-leucine, L-valine, L-isoleucine, L-cystine; AAB-2: L-arginine, L-leucine, L-valine, L-isoleucine, L-cystine, L-tryptophan) for 28 days. Fecal consistency was ranked daily, growth performance was assessed weekly. On day 1 and 14 of the trial, blood samples were collected from a subset of 10 piglets per group to assess concentrations of insulin-like growth factor 1. After 28 days of feeding, tissues were obtained from the same piglets to analyze gut morphology and relative mRNA expression of genes related to gut function. Even if the stress response as indicated by rectal temperature was not different between the groups, pigs supplemented with AAB-2 showed firmer feces after weaning and less days with diarrhea compared to control. Furthermore, the jejunal expression of the MUC-2 gene was reduced (P &lt; 0.05) in group AAB-2. Both amino acid mixtures increased crypt depth in the duodenum. Collectively, the given results indicate that 0.3 % extra amino acid supplementation might alleviate post-weaning diarrhea but did not alter growth performance of weanling piglets.