Impact of the environment on the microbiome

Effect of gut microbiome on serotonin metabolism: a personalized treatment approach

Several factors including diet, exercise, and medications influence the makeup of the resilient but adaptable gut microbiome. Bacteria in the gut have a significant role in the homeostasis of the neurotransmitter serotonin, also known as 5-hydroxytryptamine, involved in mood and behavior. The goal of the current work is to review the effect of the gut microbiome on serotonin metabolism, and how it can potentially contribute to the development of a personalized treatment approach for depression and anxiety. Bacterial strains provide innovative therapeutic targets that can be used for disorders, such as depression, that involve dysregulation of serotonin. Advances in bacterial genomic sequencing have increased the accessibility and affordability of microbiome testing, which unlocks a new targeted pathway to modulate serotonin metabolism by targeting the gut-brain axis. Microbiome testing can facilitate the recommendation of strain-specific probiotic supplements based on patient-specific microbial profiles. Several studies have shown that supplementation with probiotics containing specific species of bacteria, such as Bifidobacterium and Lactobacillus, can improve symptoms of depression. Further research is needed to improve the process and interpretation of microbiome testing and how to successfully incorporate testing results into guiding clinical decision-making. This targeted approach centered around the gut-brain axis can provide a novel way to personalize therapy for mental health disorders.

Removal of leftover feed shapes environmental microbiota and limits houseflies-mediated dispersion of pathogenic bacteria in sow breeding farms

BACKGROUND

Intensive swine breeding industry generates a complex environment where several microbial interactions occur and which constitutes a challenge for biosafety. Ad libitum feeding strategies and low levels of management contribute to residual and wasted feed for lactating sows, which provides a source of nutrients and microbial source for houseflies in warm climates. Due to the absence of the all-in/all-out system, the coexistence of sows of two production stages including gestating and lactating sows in the farrowing barn may have potential negative impacts. In this research, we evaluated the effects of lactating sow leftover on the environmental microbiota of the farrowing barn and the contribution of microbial environments to the gestating sow fecal bacterial structure with a 30-day-long treatment of timely removing lactating residual feed.

RESULTS

Houseflies in the farrowing barn mediate the transmission of microorganisms from lactating sow leftover to multiple regions. Leuconostoc, Weissella, Lactobacillus and Pediococcus from the leftover which can produce exopolysaccharides, are more capable of environmental transmission than pathogenic microorganisms including Staphylococcus and Streptococcus and utilize houseflies to achieve spread in environmental regions of the farrowing barn. Leftover removal treatment blocked the microbial transmission chain mediated by houseflies, downregulated the relative abundance of pathogenic bacteria including Escherichia-Shigella and Streptococcus among houseflies, environmental regions and fecal bacteria of gestating sows in the farrowing barn and effectively attenuate the increment of Weissella and RF39 relative abundance in gestating sow feces due to the presence of lactating sows.

CONCLUSIONS

Lactating sow leftover is a non-negligible microbial contributor of environment in farrowing barn whose transmission is mediated by houseflies. A 30-day-long treatment of removing lactating sow residual feed cause significant changes in the microbial structure of multiple environmental regions within the farrowing barn via altering the microbiota carried by houseflies. Meanwhile, lactating sow leftover affect the fecal microbial structure of gestating sows in the same farrowing barn, while removal of lactating sow leftover alleviates the contribution of microbial transmission.

Parental, gestational, and early-life exposure to indoor environmental hazardous factors on allergic rhinitis among preschool children in Urumqi City: a case-control study

OBJECTIVE

Allergic rhinitis (AR) is a disease associated with impaired quality of life and heredity. This study aimed to investigate the association of allergic rhinitis in preschool children with exposure to indoor environment-related factors early in life.

METHODS

In August 2019, the authors implemented a study among 2020 preschool children in Urumqi City using a case-control design. The study included parental reports for the occurrence of AR in children, parental history of respiratory disease, and indoor environmental correlates of maternal exposure from 1 year prior to pregnancy until the child's age of 0-1 year.

RESULTS

Mode of birth (cesarean section) (OR = 1.31, 95% CI = 1.02∼1.67), father with AR (OR = 2.67, 95% CI = 2.08∼3.44), mother with AR (OR = 3.70, 95% CI = 2.88∼4.74), mother with asthma (OR = 3.11, 95% CI = 1.18∼8.20), and mother with newly purchased furniture in the parents' residence during pregnancy (OR = 1.49, 95% CI = 1.03∼2.14) were risk factors for AR in children.

CONCLUSIONS

The focus of allergic rhinitis should be on children with a family history of AR and asthma and cesarean delivery. Primary prevention efforts for AR in preschool children are avoiding exposure of children to indoor environmental hazardous factors early in life.

Microbiome Changes in Pregnancy Disorders

The human microbiota comprises all microorganisms, such as bacteria, fungi, and viruses, found within a specific environment that live on our bodies and inside us. The last few years have witnessed an explosion of information related to the role of microbiota changes in health and disease. Even though the gut microbiota is considered the most important in maintaining our health, other regions of the human body, such as the oral cavity, lungs, vagina, and skin, possess their own microbiota. Recent work suggests a correlation between the microbiota present during pregnancy and pregnancy complications. The aim of our literature review was to provide a broad overview of this growing and important topic. We focused on the most significant changes in the microbiota in the four more common obstetric diseases affecting women's health. Thus, our attention will be focused on hypertensive disorders, gestational diabetes mellitus, preterm birth, and recurrent miscarriage. Pregnancy is a unique period in a woman's life since the body undergoes different adaptations to provide an optimal environment for fetal growth. Such changes also involve all the microorganisms, which vary in composition and quantity during the three trimesters of gestation. In addition, special attention will be devoted to the potential and fundamental advances in developing clinical applications to prevent and treat those disorders by modulating the microbiota to develop personalized therapies for disease prevention and tailored treatments.

Microbiota, IgA and Multiple Sclerosis

Multiple sclerosis (MS) is a neuroinflammatory disease characterized by immune cell infiltration in the central nervous system and destruction of myelin sheaths. Alterations of gut bacteria abundances are present in MS patients. In mouse models of neuroinflammation, depletion of microbiota results in amelioration of symptoms, and gavage with MS patient microbiota exacerbates the disease and inflammation via Th17 cells. On the other hand, depletion of B cells using anti-CD20 is an efficient therapy in MS, and growing evidence shows an important deleterious role of B cells in MS pathology. However, the failure of TACI-Ig treatment in MS highlighted the potential regulatory role of plasma cells. The mechanism was recently demonstrated involving IgA+ plasma cells, specific for gut microbiota and producing IL-10. IgA-coated bacteria in MS patient gut exhibit also modifications. We will focus our review on IgA interactions with gut microbiota and IgA+ B cells in MS. These recent data emphasize new pathways of neuroinflammation regulation in MS.