bims-metalz Biomed News
on Metabolic causes of Alzheimer’s disease
Issue of 2023‒08‒13
five papers selected by
Mikaila Chetty
Goa University

  1. Semin Neurol. 2023 Aug 10.
      The human gastrointestinal tract is home to trillions of microorganisms-collectively referred to as the gut microbiome-that maintain a symbiotic relationship with their host. This diverse community of microbes grows and changes as we do, with developmental, lifestyle, and environmental factors all shaping microbiome community structure. Increasing evidence suggests this relationship is bidirectional, with the microbiome also influencing host physiological processes. For example, changes in the gut microbiome have been shown to alter neurodevelopment and have lifelong effects on the brain and behavior. Age-related changes in gut microbiome composition have also been linked to inflammatory changes in the brain, perhaps increasing susceptibility to neurological disease. Indeed, associations between gut dysbiosis and many age-related neurological diseases-including Parkinson's disease, Alzheimer's disease, multiple sclerosis, and amyotrophic lateral sclerosis-have been reported. Further, microbiome manipulation in animal models of disease highlights a potential role for the gut microbiome in disease development and progression. Although much remains unknown, these associations open up an exciting new world of therapeutic targets, potentially allowing for improved quality of life for a wide range of patient populations.
  2. Semin Neurol. 2023 Aug 10.
      The gut-brain axis refers to a bidirectional communication pathway linking the gastrointestinal system to the central nervous system. The hardware of this multifaceted pathway takes many forms, at once structural (neurons, microglia, intestinal epithelial cell barrier), chemical (neurotransmitters, enteroendocrine hormones, bacterial metabolites), and cellular (immune signaling, inflammatory pathways). The gut-brain axis is exquisitely influenced by our environment, diet, and behaviors. Here, we will describe recent progress in understanding the gut-brain axis in neurological disease, using Parkinson's disease as a guide. We will see that each component of the gut-brain axis is heavily mediated by intestinal microbiota and learn how gut-brain communication can go awry in microbial dysbiosis.
  3. Semin Cell Dev Biol. 2023 Aug 09. pii: S1084-9521(23)00144-1. [Epub ahead of print]
    Keywords:  Aging; Anchor cell invasion; Apoptosis; Immunity; Lifespan; MicroRNA; Mitochondria; Mitophagy; Neurodegeneration; Programmed cell death; Proteotoxicity; UPR(mt); Unfolded protein response
  4. Geroscience. 2023 Aug 10.
      Aging is associated with cellular and physiological changes, which significantly reduce the quality of life and increase the risk for disease. Geroprotectors improve lifespan and slow the progression of detrimental aging-related changes such as immune system senescence, mitochondrial dysfunction, and dysregulated nutrient sensing and metabolism. Emerging evidence suggests that gut microbiota dysbiosis is a hallmark of aging-related diseases and microbiome modulators, such as probiotics (live bacteria) or postbiotics (non-viable bacteria/bacterial byproducts) may be promising geroprotectors. However, because they are strain-specific, the geroprotective effects of probiotics and postbiotics remain poorly understood and understudied. Drosophila melanogaster, Caenorhabditis elegans, and rodents are well-validated preclinical models for studying lifespan and the role of probiotics and/or postbiotics, but each have their limitations, including cost and their translation to human aging biology. C. elegans is an excellent model for large-scale screening to determine the geroprotective potential of drugs or probiotics/postbiotics due to its short lifecycle, easy maintenance, low cost, and homology to humans. The purpose of this article is to review the geroprotective effects of microbiome modulators and their future scope, using C. elegans as a model. The proposed geroprotective mechanisms of these probiotics and postbiotics include delaying immune system senescence, preventing or reducing mitochondrial dysfunction, and regulating food intake (dietary restriction) and metabolism. More studies are warranted to understand the geroprotective potential of probiotics and postbiotics, as well as other microbiome modulators, like prebiotics and fermented foods, and use them to develop effective therapeutics to extend lifespan and reduce the risk of debilitating aging-related diseases.
    Keywords:  Aging; C. elegans; Geroscience; Gut; Microbiome; Postbiotics; Probiotics
  5. Front Nutr. 2023 ;10 1173660
      Pro-and prebiotics have been indicated to modulate the gut-brain axis, which have supportive impacts on central nervous systems, and decrease or control the incidence of some mental disorders such as depression, anxiety, autism, Schizophrenia, and Alzheimer's. In this review, complex communications among microbiota, gut, and the brain, and also recent scientific findings of the impacts and possible action mechanisms of pro-and prebiotics on mental disorders have been discussed. The results have shown that pro-and prebiotics can improve the function of central nervous system and play an important role in the prevention and treatment of some brain disorders; however, in order to prove these effects conclusively and firmly and to use these compounds in a therapeutic and supportive way, more studies are needed, especially human studies/clinical trials.
    Keywords:  Alzheimer’s; anxiety; depression; gut microbiome; gut-brain axis; mental disorders; prebiotics; probiotics