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The nature of a steady gut microbiota (including number and variety of the microorganisms) is influenced by various factors including mode of delivery at birth, gender, medications, genetics, age, diet, lifestyle, supplements like prebiotics and probiotics, unwanted impacts like stress, and geographical location.
Source publication
The human gastrointestinal tract hosts trillions of microorganisms that is called “gut microbiota.” The gut microbiota is involved in a wide variety of physiological features and functions of the body. Thus, it is not surprising that any damage to the gut microbiota is associated with disorders in different body systems. Probiotics, defined as livi...
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Purpose
Antibiotics prescription in early life can cause dysbiosis, an imbalance of gut microbiota. We aimed to reveal the relationship between antibiotics exposure during the first 2 years after birth and type 1 diabetes risk in children under 8 years of age using a nationally representative data from South Korea.
Methods
The final study populati...
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Citations
... It has been postulated that modulation of the gut microbiome or consumption of specific probiotics might lead to beneficial changes in CNS functions. 15 We have previously demonstrated that, in IBS patients with diarrhea or mixed bowel habits, a 6-week intervention with the probiotic Bifidobacterium longum subsp. longum (BL) NCC3001 reduced depression scores and responses to negative emotional stimuli in multiple brain areas, including the amygdala and fronto-limbic regions, compared to placebo. ...
Our recent randomized, placebo-controlled study in Irritable Bowel Syndrome (IBS) patients with diarrhea or alternating bowel habits showed that the probiotic Bifidobacterium longum (BL) NCC3001 improves depression scores and decreases brain emotional reactivity. However, the involved metabolic pathways remain unclear. This analysis aimed to investigate the biochemical pathways underlying the beneficial effects of BL NCC3001 using metabolomic profiling. Patients received probiotic (1x 10¹⁰CFU, n=16) or placebo (n=19) daily for 6 weeks. Anxiety and depression were measured using the Hospital Anxiety and Depression Scale. Brain activity in response to negative emotional stimuli was assessed by functional Magnetic Resonance Imaging. Probiotic fecal abundance was quantified by qPCR. Quantitative measurement of specific panels of plasma host-microbial metabolites was performed by mass spectrometry-based metabolomics. Probiotic abundance in feces was associated with improvements in anxiety and depression scores, and a decrease in amygdala activation. The probiotic treatment increased the levels of butyric acid, tryptophan, N-acetyl tryptophan, glycine-conjugated bile acids, and free fatty acids. Butyric acid concentration correlated with lower anxiety and depression scores, and decreased amygdala activation. Furthermore, butyric acid concentration correlated with the probiotic abundance in feces. In patients with non-constipation IBS, improvements in psychological comorbidities and brain emotional reactivity were associated with an increased abundance of BL NCC3001 in feces and specific plasma metabolites, mainly butyric acid. These findings suggest the importance of a probiotic to thrive in the gut and highlight butyric acid as a potential biochemical marker linking microbial metabolism with beneficial effects on the gut-brain axis.
... Produced CRH released from the axon terminals may stimulate the production of endotoxins (ET) in the gut (Herman et al. 2016;Fung et al. 2017;Misiak et al. 2020;Sheng et al. 2021;Hinds and Sanchez 2022). These ETs regulate the secretion of neurotransmitter precursor compounds responsible for gut microbiota interaction with CNS (Strandwitz 2018;García-Cabrerizo et al. 2021;Salami 2021;Miri et al. 2023). Later on, secreted neurotransmitter precursor compounds are transported to the brain (CNS) from the gut via the vagus nerve. ...
In the central nervous system, bidirectional communication between the brain and gut results in memory formation due to synaptic plasticity changes. During a healthy state, oral balanced microflora plays a pivotal role in memory formation by inhibiting the enterotoxin level produced by infectious pathogens. In disease conditions, beneficial microbial dysbiosis may result in excess enterotoxin production. Further, excess enterotoxin secretion prevents beneficial bacteria's proliferation and impairs neurotransmitter precursor compounds' transport to the brain. Blockade of neurotransmitter precursor compounds may result in the development of memory loss. The present study stated the role of Lactobacillus acidophilus in recovering memory loss. Reversal of cognitive impairment is shown with the help of a three-step behavioural analysis, which consists of one pre-infusive behavioural analysis and two post-infusive behavioural analyses (phase 1 and 2). The pre-infusive analysis showed no cognitive impairment in an assimilated environment without any infusions. After oral microbial infusions, phase 1 of post-infusive behavioural analysis showed the presence of cognitive impairment in the experimental groups who received oral infusions. Formed cognitive impairment is reverted with the help of L. acidophilus oral infusion in phase 2 of post-infusive analysis. Comparative three-step behavioural analysis proved that Pseudomonas aeuroginosa induced cognitive impairment may revert to normal conditions with the help of L. acidophilus. The outcome of the present study proves that cognitive impairment developed due to poor oral hygiene can be treated with the help of probiotic microorganisms.
... Within the gut microbiota, LAB have emerged as one of the key players in this intricate communication with the brain [68,69]. LAB possess the ability to influence neurotransmitter production, regulate neuroinflammation, and modulate neural pathways involved in stress response and mood regulation [70,71]. ...
... Спосіб життя вважають потенційним чинником, що впливає на здатність пробіотиків змінювати когнітивні функції. У літературі наголошено на необхідності розглядати спосіб життя як контрольну змінну в дослідженнях мікробіому [7,53]. ...
Nonalcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases in the world, affecting 25 — 30% of the adult population. Prevalence rates vary by country, with the highest rates reported in regions with the high levels of stress. The frequency of NAFLD correlates with the intensity of the subjective feeling of stress. The war in Ukraine and the migration of a part of the population to European countries had a significant impact on the health of the population, which was caused by a sharp increase in the influence of stressful factors and the formation of signs of mental health disorders. The chronic influence of negative psychosocial factors, in particular the stressful conditions of wartime, is the main reason for the hyperactivation of the stress response and chronic high cortisol levels, which become maladaptive and lead to distant consequences — changes in carbohydrate and lipid metabolism, energy balance, and metabolic changes that cause the formation of and progression of NAFLD, as well as to changes in the immune system. In addition to metabolic factors, chronic stress is a trigger for changes in the functioning of the digestive system and intestinal microbiota, that is, the gut‑liver axis, which is involved in the formation of NAFLD. The presented data justify the need for scientific research to find pathogenetic measures that affect mental processes in humans through the correction of the microbiome, namely psychobiotics — probiotics, the consumption of which in a certain amount has a beneficial effect on the host's mental health through interaction with commensal intestinal bacteria. Despite some progress in the study of the effectiveness of psychobiotics in stress management, the number of studies on this problem is limited, so it is necessary to conduct additional studies on their use in the complex treatment of NAFLD with account of lifestyle factors.
... Cognitive function, on the other hand, is less well-studied in patients with IBS and other DGBIs in spite of its close relationship with emotional function (see e.g., [18]) and its key role in a gut-brain perspective. Cognitive function with its neuronal substrate has been related to the dynamics of specific integrated networks in the brain [19][20][21] and also to the gut microbiome [22,23], referring to a community of trillions of microorganisms (bacteria, fungi, viruses) residing within the human gastrointestinal tract. These microorganisms are commonly referred to as "gut microbiota" and are characterized by their composition, diversity, mutualistic relationships, spatial distribution and dynamic colonization. ...
Introduction: Irritable bowel syndrome (IBS) is characterized as a disorder of the gut–brain interaction (DGBI). Here, we explored the presence of problems related to executive function (EF) in patients with IBS and tested the relative importance of cognitive features involved in EF. Methods: A total of 44 patients with IBS and 22 healthy controls (HCs) completed the Behavior Rating Inventory of Executive Function (BRIEF-A), used to identify nine EF features. The PyCaret 3.0 machine-learning library in Python was used to explore the data, generate a robust model to classify patients with IBS versus HCs and identify the relative importance of the EF features in this model. The robustness of the model was evaluated by training the model on a subset of data and testing it on the unseen, hold-out dataset. Results: The explorative analysis showed that patients with IBS reported significantly more severe EF problems than the HC group on measures of working memory function, initiation, cognitive flexibility and emotional control. Impairment at a level in need of clinical attention was found in up to 40% on some of these scales. When the nine EF features were used as input to a collection of different binary classifiers, the Extreme Gradient Boosting algorithm (XGBoost) showed superior performance. The working memory subscale was consistently selected with the strongest importance in this model, followed by planning and emotional control. The goodness of the machine-learning model was confirmed in an unseen dataset by correctly classifying 85% of the IBS patients. Conclusions: The results showed the presence of EF-related problems in patients with IBS, with a substantial impact of problems related to working memory function. These results suggest that EF should be part of an assessment procedure when a patient presents other symptoms of IBS and that working memory function should be considered a target when treating patients with the disorder. Further studies should include measures of EF as part of the symptom cluster characterizing patients with IBS and other DGBIs.
... A recent study in the Japanese population has revealed that the intake of natto, a fermented soybean product may contribute to reducing the risk of disabling dementia in women, especially in those aged under 60 years [21]. Presently, more and more studies have been focusing on the impact of gut microbiota towards neurological health [22]. Neuroprotection refers to the strategies and mechanisms used to guard the central nervous system (CNS) against injury due to both chronic ND, such as dementia, Parkinson's, Alzheimer's, and epilepsy, and acute ND, such as trauma or stroke [23]. ...
Background:
In recent years, the potential role of probiotics has become prominent in the discoveries of neurotherapy against neurodegenerative diseases, such as Alzheimer's and Parkinson's diseases. Lactic acid bacteria (LAB) exhibit neuroprotective properties and exert their effects via various mechanisms of actions. This review aimed to evaluate the effects of LAB on neuroprotection reported in the literature.
Methods:
A database search on Google Scholar, PubMed, and Science Direct revealed a total of 467 references, of which 25 were included in this review based on inclusion criteria which comprises 7 in vitro, 16 in vivo, and 2 clinical studies.
Results:
From the studies, LAB treatment alone or in probiotics formulations demonstrated significant neuroprotective activities. In animals and humans, LAB probiotics supplementation has improved memory and cognitive performance mainly via antioxidant and anti-inflammatory pathways.
Conclusions:
Despite promising findings, due to limited studies available in the literature, further studies still need to be explored regarding synergistic effects, efficacy, and optimum dosage of LAB oral bacteriotherapy as treatment or prevention against neurodegenerative diseases.
... Gut microbiota can also alter gene expression, neurotransmitter release, receptor function and concentrations of metabolites within the digestive tract that are vital for the bidirectional communication between the gut and brain (Salami, 2021). For example, gut dysbiosis can alter tryptophan metabolism which affects serotonergic signalling (Whiley et al., 2021). ...
... Alternatively, SCFAs may signal to the brain indirectly via the actions of peptide hormones (Christiansen et al., 2018) or cytokines (Mirmonsef et al., 2012). Gut dysbiosis decreases SCFA levels which not only attenuates anti-inflammatory functions but also alters neuronal signalling which may impair cognitive function (Salami, 2021). ...
Obesity is a major global health concern, with prevalence rates rapidly rising due to increased availability of highly processed foods rich in fats and/or sugars and technological advances promoting more sedentary behaviour. There is increasing evidence to suggest that obesity predisposes individuals to developing cognitive impairment and dementia. However, the relationship between the brain and the peripheral metabolic state is complex, and many of the underlying mechanisms of cognitive impairment in obesity are yet to be fully elucidated. To better understand the links between obesity and dementia, further work is required to determine pathological changes occurring in the brain during obesity. In this mini-review, we discuss the role of two pathological features of obesity (the gut-brain axis and systemic inflammation) and their potential contribution to dementia.
... As we previously hypothesized, it is plausible that lifestyle factors such as diet, physical activity or exposure to natural environments exert some type of regulation over probiotic effectiveness, given the well-documented effects these habits have on the microbiome [18,59,79,80]. In fact, lifestyle behaviors have been referred to as potential confounders of probiotic effects on cognitive functions and the scientific literature have consistently highlighted the need for lifestyle behaviors to be considered as control variables in microbiome research [67,79,[81][82][83][84]. ...
Psychobiotics are modulators of the Microbiota-Gut-Brain Axis (MGBA) with promising benefits to mental health. Lifestyle behaviors are established modulators of both mental health and the MGBA. This randomized placebo-controlled clinical trial (NCT04823533) on healthy adults (N = 135) tested 4 weeks of probiotic supplementation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175). We assessed effects on wellbeing, quality of life, emotional regulation, anxiety, mindfulness and interoceptive awareness. We then analyzed if lifestyle behaviors modulated probiotic effectiveness. Results showed no significant effects of probiotic intake in whole sample outcomes. Correlational analyses revealed Healthy Behaviors were significantly correlated with wellbeing across scales. Moreover, the linear mixed-effects model showed that the interaction between high scores in Healthy Behaviors and probiotic intake was the single significant predictor of positive effects on anxiety, emotional regulation, and mindfulness in post-treatment outcomes. These findings highlight the relevance of controlling for lifestyle behaviors in psychobiotic and mental health research.
... Current research shows a close relationship between several brain disorders and changes in the gut microbiota (Salami, 2021); promising favorable role of bacteria in diagnosis and/or treatment of the brain diseases. In particular, from a therapeutic point of view, it can be hypothesized whether fecal microbiota transplantation or the administration of probiotics can improve hippocampal-dependent learning and memory. ...
Introduction
It is well known that the intestinal bacteria substantially affect physiological processes in many body organs. Especially, through a bidirectional communication called as gut-microbiota-brain axis, the gut microbiota deeply influences development and function of the nervous system. Hippocampus, as a part of medial temporal lobe, is known to be involved in cognition, emotion, and anxiety. Growing evidence indicates that the hippocampus is a target of the gut microbiota. We used a broad search linking the hippocampus with the gut microbiota and probiotics.
Methods
All experimental studies and clinical trials published until end of 2021 were reviewed. Influence of the gut microbiota on the behavioral, electrophysiological, biochemical and histological aspects of the hippocampus were evaluated in this review.
Results
The effect of disrupted gut microbiota and probiotic supplements on the microbiota-hippocampus link is also considered. Studies show that a healthy gut microbiota is necessary for normal hippocampus dependent learning and memory and synaptic plasticity. The known current mechanisms are production and modulation of neurotrophins, neurotransmitters and receptors, regulation of intracellular molecular processes, normalizing the inflammatory/anti-inflammatory and oxidative/antioxidant factors, and histological stability of the hippocampus. Activity of the hippocampal neuronal circuits as well as behavioral functions of the hippocampus positively respond to different mixtures of probiotic bacteria.
Discussion
Growing evidence from animal researches indicate a close association between the hippocampus with the gut microbiota and probiotic bacteria as well. However, human studies and clinical trials verifying such a link are scant. Since the most of papers on this topic have been published over the past 3 years, intensive future research awaits.
... Probiotics are living organisms possessing significant health benefits by contributing to intestinal microbial balance [15]. They modulate digestion, metabolism, competitive removal of pathogens, and neural plasticity [16]. Probiotics synergistically execute their actions with non-digestible foods called prebiotics [17], giving rise to synbiotics which are expected to produce superior effects compared to the activity of the probiotic or prebiotic alone [18]. ...
Objectives
The incidence of co-occurring alcohol-use disorder (AUD) and post-traumatic stress disorder (PTSD) is high, and the presence of one disorder aggravates the severity of the other. Emerging evidence shows the neuroprotective and anti-inflammation functions of psychobiotics. Hence, the study explored the effects of probiotics and synbiotic inulin on the gut- and liver-oxidative and inflammatory biomarkers in chronic alcohol exacerbation of PTSD symptoms in rats.
Methods
Young adult rats were administered 10% ethanol in a two-bottle choice test for six weeks and were subjected to single prolonged stress. Probiotics and synbiotic intervention followed this. Markers of oxido-inflammatory stress, liver functions, intestinal (faecal) metabolites, occludin expression, and histopathology of the ileum and liver were evaluated.
Results
Chronic alcohol drinking and PTSD increased oxido-inflammatory stress, markers of hepatic damage, and reduced faecal metabolites, which were attenuated by probiotic and synbiotic interventions. Furthermore, reduced immunoexpression of gut and liver occludin, with loss of barrier integrity, viable hepatocytes, congestive portal area, and shortened villi and crypt depth, were observed. Probiotic and synbiotic interventions mitigated these effects.
Conclusions
The study demonstrates that psychobiotics mitigate the detrimental effects of co-occurring chronic alcohol intake in the context of PTSD.
