Journal of Mucosal Immunology Research
Open Access

Met genomics; Strain-Resolved infant gut microbiome; Community ecology; Early-Life gut colonisation; Gut microbiome; Human immunity; Autoimmune diseases

Introduction

The gut microbiome is a diverse ecosystem of commensal bacteria, Achaea, fungus, and viruses that live in and on the body. 1 However, understanding the nature and function of the microbiota is still in its infancy because the exact composition varies from person to person and there is no definitive understanding of what truly constitutes a healthy adult gut microbial profile other than exhibiting both diversity and stability. Because of the enormous variation in microbiota composition, functional capability, as defined by metabolic pathways, may be a better indicator for the health of one’s microbiome if basic metabolic route categories are conserved across individuals [1].

The immune system’s role in the pathophysiology of MS is now well known. Among other things, genetic studies (implicating primarily immune genes as risk factors), anatomopathological studies (showing major infiltrates of immune cells), and the MS animal model, experimental autoimmune encephalomyelitis (EAE), which can be induced by immune activation against myelin peptides/ proteins, have highlighted its critical role. We did a systematic review to compile the body of evidence concerning the association between the gut microbiota and MS. Our goal was to incorporate published publications in which the gut microbiota profiles of people with and without MS were compared [2].

The introduction of novel notions on MS immunology in recent years has broadened the debate on MS environmental variables. Significant attempts have been made to comprehend the complexities of the gut environment as a potential factor in the pathophysiology of MS. Changes in the composition of the microbiome have been identified in MS patients, and novel and innovative therapy techniques are being developed [3].

Microorganisms can dwell in a variety of human bodily tissues, including the skin, urogenital tract, digestive system, and respiratory tract. The microbiota is a collection of bacteria, Achaea, viruses, and other microbes that coexist happily in the human body. Microorganisms thrive in the digestive tract, which offers critical nutrients. The gut microbiota plays an important role in the health of its host by processing undigested carbohydrates, making short-chain fatty acids (SCFA), synthesising Vitamin B and K, and protecting against pathogens. The stomach also has a complex way of connecting with other body systems, including the central nervous system (CNS). Microorganisms can dwell in a variety of human bodily tissues, including the skin, urogenital tract, digestive system, and respiratory tract. The microbiota is a collection of bacteria, Achaea, viruses, and other microbes that coexist happily in the human body. Microorganisms thrive in the digestive tract, which offers critical nutrients [4].

Gut microorganisms are critical to the development and operation of the human immune system. A disrupted gut microbiota composition is frequently linked to a variety of health problems, including immunemediated diseases. In inter-continental comparison studies, differences in host variables such as ethnicity, lifestyle, and diet have been used to explain variances in gut microbiota composition. As prior research has shown that daily skin contact with organic gardening materials alters gut microbiota, we explored the relationship between living environment and gut microbiota in a homogeneous western population along an urban-rural gradient. In August and November 2015, we collected stool samples from 48 native senior Finns in the province of Häme and used 16S rRNA Illumina MiSeq sequencing to identify the bacterial phenotypes [5]. In generalised linear mixed models, we assumed that yard vegetation and land cover classes surrounding residences explain the stool bacterial community. Diverse yard vegetation was linked to lower levels of Clostridium sensu stricto and higher levels of Faecalibacterium and Prevotellaceae. Bacteroides abundance was found to be positively and substantially related to the built environment. The exclusion of animal owners had little effect on the key associations. These findings imply that diverse vegetation near dwellings is linked to changes in gut microbiota composition that affect health. Garden diversity manipulation, possibly in collaboration with urban planning, is a promising possibility for future intervention research aimed at maintaining gut homeostasis [6].

Materials and methods

We ran a literature search using the terms Gut Microbiota, Dysbiosis, Gut Microbiota Dysregulation, Brain, Bowel Disease, Inflammation, Mood Disorders, and Affective Symptoms in various combinations in the electronic database MEDLINE/PubMed/Index Medicus. The literature search, title/abstract screening, and full text screening were carried out by two independent investigators (FB and AM) [7]. The reference list of selected publications was screened again to look for additional literature. Original research reporting data on the putative association between gut microbiota dysregulation and inflammatory state, Th17 differentiation, neuroactive factors, and TRP metabolism were included in our review. Furthermore, we included research on the relationship between gut microbiota dysregulation and mood disorders or mood symptoms, with a focus on the prevalence and potential therapeutic implications of this link. For inclusion, research completed at any time up to September 30, 2021 was considered. Articles that did not contain original data, letters to the editor, commentaries, and case studies were not accepted. There were no language restrictions [8].

Discussion

In this narrative review, we first looked at the links between dysregulated gut microbiota and inflammation, as well as the implications of these disruptions on Th17 regulation. We then considered the relationship between dysregulated gut microbiota and neuroactive factors, the most relevant of which appear to be those involved in tryptophan metabolism. Furthermore, we presented evidence for a link between gut microbiota dysregulation and mood disorders, as well as mood symptoms that arise in the context of medical conditions [9].

In all aspects investigated, the association between inflammation (expressed as dysbiosis, T lymphocyte predominance, and neurotransmitter metabolism) and mood disorders appears to be narrow [10].

Results

We use a narrative technique to convey data from the literature. The findings will be organised into the following chapters: Gut microbiota dysregulation and inflammatory state, Th17 differentiation, neuroactive factors, TRP metabolism, and mood disorders Mood symptoms in medical disorders caused by disruption of the gut microbiota. Participants with one or more noncommunicable chronic disorders impacting the immune response, such as diabetes, rheumatoid arthritis, chronic obstructive pulmonary disease, celiac disease, psoriasis, dementia, multiple sclerosis, asthma with cortisol therapy, or cancer, were excluded (active treatment during the last year or largely spread). Daily smokers, immunosuppressive medicine, and cortisone medications were also excluded. Before statistical analysis, participants who had had antibiotics during the previous six months were excluded. Participants who owned indoor pets or outdoor domestic animals (cat, dog, cow, horse, chicken, and pig) were later segregated from the original dataset and studied the effect of animal ownership on gut microbiota composition in future statistical analyses (details below).

Conclusion

There is some data that suggests a link between gut microbiota and MS development. However, the precise origin of changes in gut microbiota composition and the processes leading MS activation remain unknown. Further research should be conducted to study these mechanisms and how they can be altered. Because there are no specific biomarkers for MS, the composition of the gut microbiota may be a possibility to predict the chance of MS incidence. The majority of research found no difference in gut microbiota diversity between MS patients and controls. Taxonomic distinctions, however, were discovered, with consistent patterns forming across research. Longitudinal investigations are needed to determine the link between IMD exposure and variations in gut microbiota composition. Recent research in this field supports our idea that gut microbiota imbalance can play a role in the genesis of numerous neuropsychiatric illnesses, particularly mood disorders. The gut microbiota and its changes appear to play a role in the development of mental diseases, particularly mood disorders. As a result, our theory could serve as a guide for future experimental studies. Because animal models do not precisely replicate the normal evolution of human illnesses, it is critical to increase the number of human-based studies. The current body of knowledge on the subject is still developing, with an emphasis on both molecular etiopathogenesis and clinical correlations.

Acknowledgement

None

Conflict of interest

All authors declare no conflict of interest.

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