Review of the scientific evidence and technical opinion on noncaloric sweetener consumption in gastrointestinal diseases

Digestive Enzyme Activities, Oxidative Status and Intestinal Histomorphometry of Rats Supplemented with Steviana, A Natural Sweetener

<b>Background and Objective:</b> Stevia (<i>Stevia rebaudiana</i>), often known as sweet leaf, is a perennial plant and a member of the Asteraceae family. The commercial version of stevia leaf powder, known as Steviana, is one of the most popular natural sweeteners in use today. The current study aimed to analyze the activities of gut digestive enzymes, intestinal oxidative state and intestinal histological structure in stevia-fed rats. <b>Materials and Methods:</b> In this study, male rats were given Steviana and the oxidative condition of the gastrointestinal tract (GIT), the activities of certain digestive enzymes and the histomorphology of the GIT were examined. Animals used in experiments were split into 2 groups: Control and treated groups. For four consecutive weeks, the treatment group received a daily oral intake of 5 mg kg¹ b.wt., of Steviana solution. At the end of the trial, serum, pancreas and intestinal tissue samples were taken. <b>Results:</b> The Steviana sweetener has a strong antioxidative effect on both blood and intestinal tissue. Both sample types showed a decrease in malondialdehyde levels and a marked increase in superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities compared to control samples. In samples of blood, pancreas and intestinal contents, the activities of digestive enzymes including α-amylase, lipase and protease were significantly elevated in Steviana-treated rats. In addition, histological analysis of the small intestine showed that in rats given Steviana sweetener, intestinal glandular crypt depth was more pronounced compared to the control animals. <b>Conclusion:</b> In summary, consumption of Steviana appears to enhance digestion and absorption processes through antioxidative effects, improving the health of the local GIT and subsequently accelerating the rate of synthesis and release of endogenous digestive enzymes. Another aspect that enhances the digestion and absorption process is the change in the histological structure of the intestinal glands, as shown by an increase in the crypt depth.

A sweeter future: Using protein language models for exploring sweeter brazzein homologs

With growing concerns over the health impact of sugar, brazzein offers a viable alternative due to its sweetness, thermostability, and low risk profile. Here, we demonstrated the ability of protein language models to design new brazzein homologs with improved thermostability and potentially higher sweetness, resulting in new diverse optimized amino acid sequences that improve structural and functional features beyond what conventional methods could achieve. This innovative approach resulted in the identification of unexpected mutations, thereby generating new possibilities for protein engineering. To facilitate the characterization of the brazzein mutants, a simplified procedure was developed for expressing and analyzing related proteins. This process involved an efficient purification method using Lactococcus lactis (L. lactis), a generally recognized as safe (GRAS) bacterium, as well as taste receptor assays to evaluate sweetness. The study successfully demonstrated the potential of computational design in producing a more heat-resistant and potentially more palatable brazzein variant, V23.

Irritable bowel syndrome-like symptoms before and after bariatric surgery and association with short-chain fermentable carbohydrates consumption: an observational prospective study

Background and aims

Irritable Bowel Syndrome (IBS)-like symptoms are frequent following bariatric surgery. This study aims to evaluate the frequency of IBS symptoms severity before and after bariatric surgery and their association with short-chain fermentable carbohydrates (FODMAPs) consumption.

Patients and methods

IBS symptoms severity in a cohort of obese patients was evaluated prospectively before, 6 and 12 months after bariatric surgery by validated questionnaires and tools (Irritable Bowel Syndrome Severity Scoring System (IBS SSS), Bristol Stool Scale (BSS), Quality of Life Short- Form-12 (SF-12), Hospital Anxiety and Depression scale (HAD)). FODMAPs consumption and its association with IBS symptom severity was evaluated by using a food frequency questionnaire focused on high-FODMAPs food consumption.

Results

Fifty-one patients were included (41 female; mean age 41 years (SD: 12)), 84% received a sleeve gastrectomy, and 16% a Roux-en-Y gastric bypass. Symptoms compatible with IBS were observed in 43% of patients before surgery, in 58% of patients at 6 months and 33% at 12 months (NS, p-value=0,197 and 0,414). In a multivariate model, a significant association was found between the IBS SSS score and lactose consumption at 6 months (β = + 58, 1; p = 0.03), and with polyols consumption at 12 months (β = + 112,6; p = 0.01).

Conclusions

Mild to moderate IBS symptoms are frequent in obese patients before bariatric surgery. A significant association between lactose and polyols consumption and IBS SSS score was observed after bariatric surgery, suggesting a potential link between the severity of IBS symptoms and some specific FODMAPs consumption.

Chronic systemic low-grade inflammation and modern lifestyle: the dark role of gut microbiota on related diseases with a focus on pandemic COVID-19

Inflammation is a physiological, beneficial and auto-limiting response of the host to alarming stimuli. Conversely, a chronic systemic low-grade inflammation (CSLGI), known as a long-time persisting condition, causes organs and host tissues' damage, representing a major risk for chronic diseases. Currently, a worldwide a high incidence of inflammatory chronic diseases is observed, often linked to the lifestyle-related changes occurred in the last decade's society. The mains lifestyle-related factors are a proinflammatory diet, psychological stress, tobacco smoking, alcohol abuse, physical inactivity, and finally indoor living and working with its related consequences such as indoor pollution, artificial light exposure and low vitamin D production. Recent scientific evidences found that gut microbiota (GM) has a main role in shaping the host's health, particularly as CSLGI mediator. As a matter of facts, based on the last discoveries regarding the remarkable GM activity, in this manuscript we focused on the elements of actual lifestyle that influence the composition and function of intestinal microbial community, in order to elicit the CSLGI and its correlated pathologies. In this scenario, we provide a broad review of the interplay between modern lifestyle, GM and CSLGI with a special focus on the COVID symptoms and emerging long-COVID syndrome.

Is a Non-Caloric Sweetener-Free Diet Good to Treat Functional Gastrointestinal Disorder Symptoms? A Randomized Controlled Trial

Background: A diet containing non-caloric sweeteners (NCS) could reduce calorie intake; conversely, some animal studies suggest that NCS consumption may increase functional gastrointestinal disorder symptoms (FGDs). This study aimed to compare the effect of consuming a diet containing NCS (c-NCS) versus a non-caloric sweetener-free diet (NCS-f) on FGDs. Methods: We conducted a randomized, controlled, parallel-group study using two different diets for five weeks: the c-NCS diet contained 50−100 mg/day NCS, whereas the NCS-f diet had less than 10 mg/day NCS. At the beginning of the study (PreTx) and at the end (PostTx), we assessed FGDs, dietary intake, and NCS consumption. Results: The percentage of participants with diarrhea (PreTx = 19% vs. PstTx = 56%; p = 0.02), post-prandial discomfort (PreTx = 9% vs. PstTx = 39%; p = 0.02), constipation (PreTx = 30% vs. PostTx = 56%; p < 0.01), and burning (PreTx = 13% vs. PostTx = 33%; p < 0.01) increased in the c-NCS diet group. Conversely, abdominal pain (PreTx = 15% vs. PostTx = 3%; p = 0.04), post-prandial discomfort (PreTx = 26% vs. PostTx = 6%; p = 0.02), burning (PreTx = 15% vs. PostTx = 0%; p = 0.02), early satiety (PreTx = 18% vs. PostTx = 3%; p < 0.01), and epigastric pain (PreTx = 38% vs. PostTx = 3%; p < 0.01) decreased in the NCS-f diet group. Conclusion: A c-NCS diet is associated with increased FGDs, including diarrhea, post-prandial discomfort, constipation, and burning or retrosternal pain. The NCS-f diet also decreased FGDs, as well as abdominal pain, post-prandial discomfort, burning or retrosternal pain, early satiety, and epigastric pain.

In Vitro Modulatory Effect of Stevioside, as a Partial Sugar Replacer in Sweeteners, on Human Child Microbiota

The effect of stevioside on human health is still insufficiently highlighted by recent research. The total or partial replacement of sugar with sweeteners influences the general state of health, especially the human microbiota's response as a determining factor in the onset of type 2 diabetes. The present study aimed to present the long-term (one-year) in vitro effect that regular stevioside consumption had on children's pattern microbiota. A metabolomic response was established by determining the synthesis of organic acids and a correlation with antioxidant status. An increase in the number of bacterial strains and the variation of amount of butyrate and propionate to the detriment of lactic acid was observed. The effect was evidenced by the progressive pH increasing, the reduction of acetic acid, and the proliferation of Escherichia coli strains during the simulations. Synthesis of the main short-chain fatty acids (SCFAs) was interpreted as a response (adaptation) of the microbiota to the stevioside, without a corresponding increase in antioxidant status. This study demonstrated the modulatory role of stevioside on the human microbiota and on the fermentation processes that determine the essential SCFA synthesis in maintaining homeostasis. The protection of the microbiota against oxidative stress was also an essential aspect of reducing microbial diversity.

Saccharin Supplementation Inhibits Bacterial Growth and Reduces Experimental Colitis in Mice

Non-caloric artificial sweeteners are frequently discussed as components of the “Western diet”, negatively modulating intestinal homeostasis. Since the artificial sweetener saccharin is known to depict bacteriostatic and microbiome-modulating properties, we hypothesized oral saccharin intake to influence intestinal inflammation and aimed at delineating its effect on acute and chronic colitis activity in mice. In vitro, different bacterial strains were grown in the presence or absence of saccharin. Mice were supplemented with saccharin before or after induction of acute or chronic colitis using dextran sodium sulfate (DSS) and the extent of colitis was assessed. Ex vivo, intestinal inflammation, fecal bacterial load and composition were studied by immunohistochemistry analyses, quantitative PCR, 16 S RNA PCR or next generation sequencing in samples collected from analyzed mice. In vitro, saccharin inhibited bacterial growth in a species-dependent manner. In vivo, oral saccharin intake reduced fecal bacterial load and altered microbiome composition, while the intestinal barrier was not obviously affected. Of note, DSS-induced colitis activity was significantly improved in mice after therapeutic or prophylactic treatment with saccharin. Together, this study demonstrates that oral saccharin intake decreases intestinal bacteria count and hence encompasses the capacity to reduce acute and chronic colitis activity in mice.