Association between Probiotics and Modulation of Gut Microbial Community Composition in Colorectal Cancer Animal Models: A Systematic Review (2010-2021).

Background: Colorectal cancer (CRC) is one of the most prevalent gastrointestinal malignancies and is considered the third major cause of mortality globally. Probiotics have been shown to protect against the CRC cascade in numerous studies. Aims: The goal of this systematic review was to gather the preclinical studies that examined the impact of probiotics on the alteration of gut microbiota profiles (bacterial communities) and their link to colorectal carcinogenesis as well as the potential processes involved. Methods: The search was performed using Scopus, Web of Science, and PubMed databases. Five parameters were used to develop search filters: "probiotics," "prebiotics," "synbiotics," "colorectal cancer," and "animal model." Results: Of the 399 full texts that were screened, 33 original articles met the inclusion criteria. According to the current findings, probiotics/synbiotics could significantly attenuate aberrant crypt foci (ACF) formation, restore beneficial bacteria in the microbiota population, increase short-chain fatty acids (SCFAs), and change inflammatory marker expression. Conclusions: The present systematic review results indicate that probiotics could modulate the gut microbial composition and immune regulation to combat/inhibit CRC in preclinical models. However, where the evidence is more limited, it is critical to transfer preclinical research into clinical data.

The Influence of Probiotics Consumption on Management of Prediabetic State: A Systematic Review of Clinical Trials.

Prediabetes consists of the intermediary stage between normal glucose regulation and overt diabetes mellitus and develops when blood glucose levels are higher than normal but not high enough to confirm a type 2 diabetes mellitus diagnosis (T2DM). Recent evidence suggests that probiotics could be promising approaches to improve this state. In this study, we performed a systematic review to compile the results of clinical trials investigating the effects of pro-/pre-/synbiotics on prediabetes subjects from 2010 to 2020. The article search was carried out in Medline, Embase, Scopus, Web of Science, The Cochrane Library, Clinical trials.gov, ProQuest, Open Grey, and Google Scholar. Search filters were developed using 2 parameters: "prestate diabetes" and "probiotics." Of the 418 studies that were screened, 15 original articles reached the inclusion criteria. Pooling data from these trials showed positive and significant effects of probiotics in the reduction of hyperglycemia, insulin concentration levels, lipid profile, and BMI (Body mass index). Administration of probiotics may provide beneficial and healthful effects in the clinical management of patients with prediabetes and metabolic syndrome. Different probiotics compositions have shown beneficial and noticeable effects on glucose homeostasis, lipid profiles, BMI, and inflammatory markers in subjects with prediabetes, metabolic syndrome, and healthy individuals and could be advantageous in recomposing the gut microbiota back into the normal state during the prediabetic state.

Effect of physical stress on the alteration of mesolimbic system apoptotic factors in conditioned place preference paradigm.

Mesocorticolimbic (MCL) dopaminergic system has an essential role in the rewarding action of opiates and is proved to be influenced by stress. Additionally, both morphine and stress can induce apoptosis. In this study, we investigated the effects of morphine-induced conditioned place preference (CPP) in the presence and absence of stress on the changes of apoptotic factors (Bax/Bcl-2 ratio, caspase-3 activation and PARP degradation) in the MCL system. Male Wistar rats were divided into two saline- and morphine-treated supergroups, each of which consisted of control, acute stress (AS) and subchronic stress (SS) subgroups. In all groups, the CPP paradigm was performed; thereinafter alternations of apoptotic factors in the nucleus accumbens, amygdala, striatum and prefrontal cortex were measured. The results indicated that in the saline-treated animals, AS and SS increased apoptotic factors significantly in the mentioned areas (except for the Bax/Bcl-2 ratio after AS in the Str). In addition, in these animals, conditioning scores decreased after SS but not after AS. In the morphine-treated animals, AS and SS increased apoptotic factors remarkably (except for the Bax/Bcl-2 ratio after AS and SS in the Str and caspase-3 activation after AS in the NAc) and also decreased conditioning scores. Our findings suggest that in the saline- or morphine-treated animals, AS and SS can increase the apoptotic factors in the MCL system and it is more prominent in the morphine-treated animals.

Morphine could increase apoptotic factors in the nucleus accumbens and prefrontal cortex of rat brain's reward circuitry.

The nucleus accumbens (NAc) and prefrontal cortex (PFC) are two parts of neuronal reward circuit involved in motivated and goal-directed behaviors. Some data suggest that morphine is toxic to neurons and induces apoptosis, while other evidence shows that morphine could have beneficial effects against cell death. This study was designed to evaluate the effect of morphine on apoptosis by measuring the expression of apoptotic proteins in two important regions, the NAc and PFC, in the rat brain's reward circuitry. Morphine subchronic administration in different doses (0.5, 5 and 10mg/kg) in conditioned place preference (CPP) paradigm (3 times in 3 days, for each dose in each group of rats) was used to induce its rewarding effect. Then, the expression of four apoptotic factors; Bax, Bcl2, caspase3 and PARP, in the NAc and PFC were assessed using the Western blot technique. All of morphine-treated groups showed increase of apoptotic factors in these regions. In the NAc, morphine significantly increased the Bax/Bcl-2 ratio, caspase3 and PARP in the lowest dose (0.5mg/kg) but in the PFC considerable increase was seen in dose of 5mg/kg. Elevation of apoptotic factors in the NAc and PFC implies that morphine can affect the molecular mechanisms which interfere with apoptosis through different receptors. Our findings suggest that the NAc and PFC may have a different distribution of receptors which become active in different doses of morphine.