The digestive system of humans and animals is the main host for different microbes, as it contains a large number of pathogenic and non-pathogenic microbes. Intestinal microbes begin to form immediately after birth and are affected by the type of nutrition and environmental factors, as well as their important role in metabolism, as well as their active role in important metabolic functions in the fermentation of complex carbohydrates that cross from the digestive process, various substances consumed in the diet, fats, amino acids and proteins, breakdown of bile acids, absorption of vitamin K and many components of vitamin B, the community of bacteria that colonizes the host intestine is closely related to the various physiological functions of the host, including Digestion, nutrient metabolism, and immunity, and may also influence the host's adaptation to the environment and evolution, therefore, the intestinal bacterial community has an important role in maintaining human life and health (Ilhan, 2018; Oliphant and Allen-Vercoe, 2019; Fülling et al., 2020). Oliver et al., (2021) reported that dietary shifts have a direct effect on the gut microbiome through a selective selection of microbes capable of utilizing different nutrients. Bogatyrev et al., (2020) also mentioned in their study that the digestive system plays a prominent role in human physiology as a primary site for enzymatic digestion and nutrient absorption, and the revival of the small intestine has been involved in various human diseases, such as non-alcoholic steatohepatitis and inflammatory bowel diseases. Gut bacteria exploit the nutrients provided by the host organism, on the other hand, the host uses many products of gut bacteria metabolism as essential material for ATP production in the colon, causing bacterial metabolites to leak from the gut into the bloodstream and interfere with the host’s cellular bioenergetics mechanism (Tomasova et al., 2021). The diverse microbial community inhabiting the human gut possesses a broad metabolic repertoire, so the gut microbiota is a major factor in shaping the biochemical profile of the diet, and thus its impact on host health and disease (Rowland et al., 2018). Rivera-Piza and Lee, (2020) note that the gut microbiota may induce metabolic diseases, such as obesity, through genetic and environmental factors and pathways linking metabolism to the immune system. And that the gut microbiota can affect the absorption of nutrients and energy storage, and thus the prevalence of obesity and metabolic disorders (Bogatyrev et al., 2020).
β-amino butyric acid (BABA) is one of the rare free compounds found in nature. It has been known to stimulate plant resistance against various pathogens such as viruses, bacteria, fungi, and worms (Prieto et al., 2021; Hegedus et al., 2022). One such promising molecule is β-aminobutyric acid (BABA), which modulates the defence system at the molecular level (Choudhary et al., 2021). Parker et al., (2021) stated that BABA has plausibly non-biological and non-terrestrial origins. β-amino butyric acid (BABA) is one of the rare free compounds found in nature. It has been known to stimulate plant resistance against various pathogens such as viruses, bacteria, fungi, and worms (Baccelli et al., 2017). Ma et al., (2020) indicated in their study that b-aminobutyric acid (BABA), which is an environmentally friendly agent, can be widely used to induce plant resistance to biotic and abiotic stress, and the results showed that adding 0.2 mM of BABA led to reduce the damage caused to plants by the effects of stress and to preserve the cell structure. Treatment with β-aminobutyric acid (BABA) increased the plants' resistance and protective ability against bacterial infections such as wheat leaf rust (Puccinia triticina) disease caused by Pseudomonas protegens (Bellameche et al., 2021). Yu et al., (2022) reported that BABA limits the reproduction of nematodes. BABA also has resistance against the necrotic fungi Rhizopus stolonifer (Li et al., 2021). A male (Sagheer and Jasim, 2020) in his study on rats showed that B-amino butyric acid (BABA) affected some immune variables of male Sprague Dawley rats infected with the bacteria pseudomonas aeruginosa.
Monitor-like receptors (TLRs) are essential immune receptors with the ability to recognize conserved molecular patterns expressed by pathogens and damaged cells (Kashani et al., 2021). Activation of TLRs can lead to a range of effects including inflammatory responses, cell cycle modification, apoptosis, or regulation of cell metabolism (Akesolo et al., 2022; Fitzgerald and Kagan, 2020). TLRs are an evolutionarily ancient family of pattern recognition receptors (Fitzgerald and Kagan, 2020). Activation of these receptors is essential for the regulation and sustainability of the inflammatory response and sensitivity to danger signals. The TLR family consists of 10 known receptors, and there is some evidence to suggest that each is expressed within human platelets, These receptors are essential for coordinating and sustaining the inflammatory response to both types of danger signals (intrinsic and extrinsic) and initiating a cascade of molecular events that lead to the initiation of autoimmunity (Hally et al., 2020).
The monitoring-like receptor (TLR-4) belongs to the family of TLR which, when activated in cells of the body, initiates a chain of events (Mohamed et al., 2022). Toll-like receptor-4 is the primary receptor for LPS and is involved in the proinflammatory response, and Toll-like-4 is expressed by different types of cells throughout the human body (Ducharme et al., 2022). TLR-4 can be considered an important target for the treatment of febrile seizures in FS rats (Zaniani et al., 2022). SARS-CoV-2-induced myocarditis and multiorgan infection may be due to TLR4 activation and aberrant TLR4 signalling and hyperinflammation in COVID-19 patients TLR4 contributes significantly to SARS-CoV-2 pathogenesis, and its overactivation also leads to a prolonged or excessive innate immune response. This makes TLR4 a promising therapeutic target in COVID-19 (Aboudounya and Heads, 2021). Activation of TLR4 signalling upregulates several pro-inflammatory cytokines and chemokines, leading to nephritis. Therefore targeting TLR4 and its downstream effectors could be an effective therapeutic intervention to prevent renal inflammation and subsequent kidney damage (Jha et al., 2021).
Sagiyan, (2010) mentioned in his study that the addition of non-protein amino acid in the formulation of drugs leads to the prolongation of the effect of drugs and maintains their efficacy, and through the development in chemistry and modern biology, the non-protein amino acid (NPAAs) has become a powerful tool for the development of peptide-based drugs. Song et al., (2021) also mentioned in their study that the introduction of α-N-methylated histidine into the peptides can improve their biological activities, membrane permeability and proteolytic stability. In a study conducted by Al-Kubaisi, (2020) on the effects of β-amino butyric acid (BABA) on male rats with type 2 diabetes, the concentration of 100 used led to positive physiological and biochemical changes in the serum of male diabetic rats, progressively with higher concentrations. This indicates that increasing the concentration gave better effects, and this is what was worked on in this study by giving a higher concentration of acid. Beta amino acids such as beta-aminobutyric acid (BABA) can predispose plants to resistance to many diseases (Tao et al. 2022).
BABA will be a useful treatment for diabetes by improving glucose metabolism and restoring oxidative stress, and may also have antioxidant properties. Also, BABA was effective in reducing DNA damage in the livers of diabetic mice (Thamir and Jasim, 2021).
Bacteria have recently shown resistance to antibiotics, prompting researchers to search for more effective antibiotics, especially anti-bacterial, which are among the most important pathogens around the world, and in some cases can be considered the main cause of important diseases, mostly due to their ability to produce many Among the virulence factors that enable it to penetrate body tissues, generate infection and resist antibiotics (Jalil et al., 2017). Given the active role that non-protein amino acid plays in various vital and abiotic processes, this study aims to know the role played by β-amino butyric acid (BABA) in influencing microbes in the digestive system.