Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2024 Nov;25(6):899-922.
doi: 10.1007/s10522-024-10128-4. Epub 2024 Aug 23.

Caloric restriction mimetics improve gut microbiota: a promising neurotherapeutics approach for managing age-related neurodegenerative disorders

Affiliations
Review

Caloric restriction mimetics improve gut microbiota: a promising neurotherapeutics approach for managing age-related neurodegenerative disorders

Ishika Singh et al. Biogerontology. 2024 Nov.

Abstract

The gut microbiota (GM) produces various molecules that regulate the physiological functionality of the brain through the gut-brain axis (GBA). Studies suggest that alteration in GBA may lead to the onset and progression of various neurological dysfunctions. Moreover, aging is one of the prominent causes that contribute to the alteration of GBA. With age, GM undergoes a shift in population size and species of microflora leading to changes in their secreted metabolites. These changes also hamper communications among the HPA (hypothalamic-pituitary-adrenal), ENS (enteric nervous system), and ANS (autonomic nervous system). A therapeutic intervention that has recently gained attention in improving health and maintaining communication between the gut and the brain is calorie restriction (CR), which also plays a critical role in autophagy and neurogenesis processes. However, its strict regime and lifelong commitment pose challenges. The need is to produce similar beneficial effects of CR without having its rigorous compliance. This led to an exploration of calorie restriction mimetics (CRMs) which could mimic CR's functions without limiting diet, providing long-term health benefits. CRMs ensure the efficient functioning of the GBA through gut bacteria and their metabolites i.e., short-chain fatty acids, bile acids, and neurotransmitters. This is particularly beneficial for elderly individuals, as the GM deteriorates with age and the body's ability to digest the toxic accumulates declines. In this review, we have explored the beneficial effect of CRMs in extending lifespan by enhancing the beneficial bacteria and their effects on metabolite production, physiological conditions, and neurological dysfunctions including neurodegenerative disorders.

Keywords: Aging; Caloric restriction mimetics; Gut microbiota; Gut-brain axis; Neurodegenerative disorders.

PubMed Disclaimer

Conflict of interest statement

The authors report that there are no competing interests to declare.

Figures

Fig. 1
Fig. 1
Aging is associated with disruption of normal gut microbiota. The gut-brain axis is a bidirectional axis that influences the functioning of the central nervous system; thus, disruption of gut microbiota can lead to neurodegenerative diseases. On the contrary calorie restriction mimetics (CRMs), through their influence on gut microbiota to secrete neurotransmitters and metabolites tend to enhance this bidirectional communication and lead to enhanced brain functioning
Fig. 2
Fig. 2
Various Calorie restriction mimetics (CRMs) and pathways they target. AMPK, Sirtuin, PI3K/Akt, and mTOR all are major pathways that are associated with autophagy. The action of different CRMs on these pathways helps to signal autophagy. AMPK and mTOR are sensor molecules, activation of AMPK and inhibition of mTOR both are responsible for the induction of autophagy. Sirtuin and PI3K also help regulate autophagy directly or indirectly through a signaling cascade
Fig. 3
Fig. 3
Nrf2-Keap1 pathway and the CRM-like ECEG leading to activation of transcription of antioxidant genes by Nrf2. Normally Nrf2 is sequestered by Keap1 in the cytoplasm leading to its degradation by proteasome. However, during oxidative stress, Nrf2 dissociates and proceeds to the nucleus leading to the transcription of genes involved in antioxidation. The association of Nrf2 with PGC-1α leads to the functioning of Nrf1 which is directly related to the process of biogenesis of mitochondria via TFAM (Transcription Factor A, Mitochondrial). EGCG is a calorie restriction mimetic that helps Nrf2 dissociate from Keap1 thus activating the antioxidation process
Fig. 4
Fig. 4
Effect of various calorie restriction mimetics (CRMs) on improved gut barrier function. CRMs like metformin, resveratrol, and spermidine stimulate the gut microbiota to secrete metabolites like SCFA, neurotransmitters that have potential benefits in enhancing blood–brain barrier permeability, managing oxidative stress, and induction of autophagy
Fig. 5
Fig. 5
Calorie restriction mimetics resveratrol and metformin effect on the release of neurotransmitters, bile acid (BA), and short-chain fatty acid (SCFA). Resveratrol and metformin through their action as CRM regulate the gut microbiota into release of these metabolites that help enhance the functioning of the brain
Fig. 6
Fig. 6
Gut brain axis (GBA). The GBA is a bidirectional axis that establishes communication between the gut microbiota and the workings of the brain

Similar articles

References

    1. Aghaie F, Moradifar F, Hosseini A (2021) Rapamycin attenuates depression and anxiety-like behaviors through modulation of the NLRP3 pathway in pentylenetetrazole-kindled male Wistar rats. Fundam Clin Pharmacol 35:1045–1054. 10.1111/fcp.12689 - PubMed
    1. Ahmad S, Khan A, Ali W et al (2021) Fisetin rescues the mice brains against D-galactose-induced oxidative stress, neuroinflammation and memory impairment. Front Pharmacol. 10.3389/fphar.2021.612078 - PMC - PubMed
    1. Ahmad F, Javed M, Athar M, Shahzadi S (2023) Determination of affected brain regions at various stages of Alzheimer’s disease. Neurosci Res 192:77–82. 10.1016/j.neures.2023.01.010 - PubMed
    1. Ahmadi S, Razazan A, Nagpal R et al (2020) Metformin reduces aging-related leaky gut and improves cognitive function by beneficially modulating gut microbiome/goblet cell/mucin axis. J Gerontol A Biol Sci Med Sci 75:e9–e21. 10.1093/gerona/glaa056 - PMC - PubMed
    1. Al-Qudah M, Anderson CD, Mahavadi S et al (2014) Brain-derived neurotrophic factor enhances cholinergic contraction of longitudinal muscle of rabbit intestine via activation of phospholipase C. Am J Physiol Gastrointest Liver Physiol 306:G328-337. 10.1152/ajpgi.00203.2013 - PMC - PubMed

MeSH terms

LinkOut - more resources