Assessing the in vivo data on low/no-calorie sweeteners and the gut microbiota

Ultra-processed foods and food additives in gut health and disease

Ultra-processed foods (UPFs) and food additives have become ubiquitous components of the modern human diet. There is increasing evidence of an association between diets rich in UPFs and gut disease, including inflammatory bowel disease, colorectal cancer and irritable bowel syndrome. Food additives are added to many UPFs and have themselves been shown to affect gut health. For example, evidence shows that some emulsifiers, sweeteners, colours, and microparticles and nanoparticles have effects on a range of outcomes, including the gut microbiome, intestinal permeability and intestinal inflammation. Broadly speaking, evidence for the effect of UPFs on gut disease comes from observational epidemiological studies, whereas, by contrast, evidence for the effect of food additives comes largely from preclinical studies conducted in vitro or in animal models. Fewer studies have investigated the effect of UPFs or food additives on gut health and disease in human intervention studies. Hence, the aim of this article is to critically review the evidence for the effects of UPF and food additives on gut health and disease and to discuss the clinical application of these findings.

Comparison of a Daily Steviol Glycoside Beverage compared with a Sucrose Beverage for Four Weeks on Gut Microbiome in Healthy Adults

BACKGROUND

Recent studies suggest that some nonnutritive sweeteners (NNS) have deleterious effects on the human gut microbiome (HGM). The effect of steviol glycosides on the HGM has not been well studied.

OBJECTIVE

We aimed to evaluate the effects of stevia- compared with sucrose-sweetened beverages on the HGM and fecal short-chain fatty acid (SCFA) profiles.

METHODS

Using a randomized, double-blinded, parallel-design study, n = 59 healthy adults [female/male, n = 36/23, aged 31±9 y, body mass index (BMI): 22.6±1.7 kg/m2] consumed 16 oz of a beverage containing either 25% of the acceptable daily intake (ADI) of stevia or 30 g of sucrose daily for 4 weeks followed by a 4-week washout. At weeks 0 (baseline), 4, and 8, the HGM was characterized via shotgun sequencing, fecal SCFA concentrations were measured using ultra-high performance liquid chromatography-tandem mass spectrometry and anthropometric measurements, fasting serum glucose, insulin and lipids, blood pressure, pulse, and 3-d diet records were obtained.

RESULTS

There were no significant differences in the HGM or fecal SCFA between the stevia and sucrose groups at baseline (P > 0.05). At week 4 (after intervention), there were no significant differences in the HGM at the phylum, family, genus, or species level between the stevia and sucrose groups and no significant differences in fecal SCFA. At week 4, BMI had increased by 0.3 kg/m2 (P = 0.013) in sucrose compared with stevia, but all other anthropometric and cardiometabolic measures and food intake did not differ significantly (P > 0.05). At week 8 (after washout), there were no significant differences in the HGM, fecal SFCA, or any anthropometric or cardiometabolic measure between the stevia and sucrose groups (P > 0.05).

CONCLUSIONS

Daily consumption of a beverage sweetened with 25% of the ADI of stevia for 4 weeks had no significant effects on the HGM, fecal SCFA, or fasting cardiometabolic measures, compared with daily consumption of a beverage sweetened with 30 g of sucrose.

TRIAL REGISTRATION

clinicaltrials.gov as NCT05264636.

Effect of the consumption of brazzein and monellin, two recombinant sweet-tasting proteins, on rat gut microbiota

Sweet-tasting proteins (SPs) are proteins of plant origin initially isolated from tropical fruits. They are thousands of times sweeter than sucrose and most artificial sweeteners. SPs are a class of proteins capable of causing a sweet taste sensation in humans when interacting with the T1R2/T1R3 receptor. SP thaumatin has already been introduced in the food industry in some countries. Other SPs, such as monellin and brazzein, are promising products. An important stage in researching SPs, in addition to confirming the absence of toxicity, mutagenicity, oncogenicity, and allergenic effects, is studying their influence on gut microbiota. In this paper we describe changes in the composition of rat gut microbiota after six months of consuming one of two recombinant SPs-brazzein or monellin. A full length 16S gene sequencing method was used for DNA library barcoding. The MaAsLin2 analysis results showed noticeable fluctuations in the relative abundances of Anaerocella delicata in brazzein-fed rat microbiota, and of Anaerutruncus rubiinfantis in monellin-fed rat microbiota, which, however, did not exceed the standard deviation. The sucrose-fed group was associated with an increase in the relative abundance of Faecalibaculum rodentium, which may contribute to obesity. Overall, prolonged consumption of the sweet proteins brazzein and monellin did not significantly change rat microbiota and did not result in the appearance of opportunistic microbiota. This provides additional evidence for the safety of these potential sweeteners.

Prebiotic potential of new sweeteners based on the simultaneous biosynthesis of galactooligosaccharides and enzymatically modified steviol glycosides

Prebiotics are known for their health-promoting functions associated with the modulation of the colonic microbiota and the products of fermentation. Recently, single-pot syntheses of galactooligosaccharides in combination with steviol glycosides (mSG-GOS) have been developed. This work was conducted to evaluate their prebiotic effect by using faecal inoculum from healthy human donors during in vitro batch fermentations. Additionally, their relative sweetness was evaluated to determine their suitability as food ingredients. The results showed a significant growth (p < 0.05) of bacteria, including the genera Bifidobacterium, Bacteroides and Clostridium, and a corresponding increase in short-chain fatty acids (SCFA) in comparison to either positive and negative controls. The sweetness equivalence to 1 % w:v of SG-GOS was 0.8 % w:v when compared to sucrose. Considering the bacteria and organic acids analyses and their sweetness values of these new biosynthesized compounds, SG-GOS could act as a prebiotic sweetener with potential health benefits warranting further evaluation through human studies.

Natural Sweetener Glycyrrhetinic Acid Monoglucuronide Improves Glucose Homeostasis in Healthy Mice

Noncaloric or low-caloric sweeteners have become popular worldwide, although debates persist regarding their impact on health. To investigate whether the sweeteners are favorable for glucose homeostasis, our study assessed the effects of glycyrrhetinic acid monoglucuronide (GAMG) and several commonly used sweeteners [glycyrrhetinic acid (GA), stevioside, erythritol, sucralose, and aspartame] on glycometabolism and elucidated the underlying mechanisms. The C57BL/6J male mice were exposed to different sweeteners for 10 weeks, and our results showed that GAMG significantly reduced fasting blood glucose (FBG) levels (FBG-control: 3.81 ± 0.42 mmol/L; FBG-GAMG: 3.37 ± 0.38 mmol/L; p < 0.05) and the blood glucose levels 15 and 30 min after sucrose or maltose loading (p < 0.05). Furthermore, it improved glucose tolerance (p = 0.028) and enhanced insulin sensitivity (p = 0.044), while the other sweeteners had negligible or adverse effects on glucose homeostasis. Subsequent experiments showed that GAMG inhibited α-glucosidases potently (IC50 = 0.879 mg·mL-1), increased three SCFA-producing bacteria and SCFAs levels (p < 0.05), and promoted the gene expression of SCFA receptor GPR43 (p = 0.018). These results suggest that GAMG may regulate blood glucose by inhibiting α-glucosidases and modulating gut microbial SCFAs. Our findings prove that GAMG, beneficial to blood glucose regulation, is a promising natural sweetener for future utilization.

Sweet Taste Receptors and Associated Sweet Peptides: Insights into Structure and Function

Long-term consumption of a high-sugar diet may contribute to the pathogenesis of several chronic diseases, such as obesity and type 2 diabetes. Sweet peptides derived from a wide range of food sources can enhance sweet taste without compromising the sensory properties. Therefore, the research and application of sweet peptides are promising strategies for reducing sugar consumption. This work first outlined the necessity for global sugar reduction, followed by the introduction of sweet taste receptors and their associated transduction mechanisms. Subsequently, recent research progress in sweet peptides from different protein sources was summarized. Furthermore, the main methods for the preparation and evaluation of sweet peptides were presented. In addition, the current challenges and potential applications are also discussed. Sweet peptides can stimulate sweetness perception by binding sweet taste receptors T1R2 and T1R3 in taste buds, which is an effective strategy for reducing sugar consumption. At present, sweet peptides are mainly prepared artificially by synthesis, hydrolysis, microbial fermentation, and bioengineering strategies. Furthermore, sensory evaluation, electronic tongues, and cell models have been used to assess the sweet taste intensity. The present review can provide a theoretical reference for reducing sugar consumption with the aid of sweet peptides in the food industry.

Exploring a Complex Interplay: Kidney-Gut Axis in Pediatric Chronic Kidney Disease

The human intestinal microbiota is a highly intricate structure with a crucial role in promoting health and preventing disease. It consists of diverse microbial communities that inhabit the gut and contribute to essential functions such as food digestion, nutrient synthesis, and immune system development. The composition and function of the gut microbiota are influenced by a variety of factors, including diet, host genetics, and environmental features. In pediatric patients, the gut microbiota is particularly dynamic and vulnerable to disruption from endogenous and exogenous factors. Recent research has focused on understanding the interaction between the gut and kidneys. In individuals with chronic kidney disease, there is often a significant disturbance in the gut microbiota. This imbalance can be attributed to factors like increased levels of harmful toxins from the gut entering the bloodstream, inflammation, and oxidative stress. This review looks at what is known about the link between a child's gut-kidney axis, how dysbiosis, or an imbalance in the microbiome, affects chronic kidney disease, and what treatments, both pharmaceutical and non-pharmaceutical, are available for this condition.

Effect of Non-Nutritive Sweeteners on the Gut Microbiota

The human gut microbiota, a complex community of microorganisms living in the digestive tract, consists of more than 1500 species distributed in more than 50 different phyla, with 99% of bacteria coming from about 30-40 species. The colon alone, which contains the largest population of the diverse human microbiota, can harbor up to 100 trillion bacteria. The gut microbiota is essential in maintaining normal gut physiology and health. Therefore, its disruption in humans is often associated with various pathological conditions. Different factors can influence the composition and function of the gut microbiota, including host genetics, age, antibiotic treatments, environment, and diet. The diet has a marked effect, impacting the gut microbiota composition, beneficially or detrimentally, by altering some bacterial species and adjusting the metabolites produced in the gut environment. With the widespread use of non-nutritive sweeteners (NNS) in the diet, recent investigations have focused on their effect on the gut microbiota as a mediator of the potential impact generated by gastrointestinal-related disturbances, such as insulin resistance, obesity, and inflammation. We summarized the results from pre-clinical and clinical studies published over the last ten years that examined the single effects of the most consumed NNS: aspartame, acesulfame-K, sucralose, and saccharin. Pre-clinical studies have given conflicting results for various reasons, including the administration method and the differences in metabolism of the same NNS among the different animal species. A dysbiotic effect of NNS was observed in some human trials, but many other randomized controlled trials reported a lack of significant impacts on gut microbiota composition. These studies differed in the number of subjects involved, their dietary habits, and their lifestyle; all factors related to the baseline composition of gut microbiota and their response to NNS. The scientific community still has no unanimous consensus on the appropriate outcomes and biomarkers that can accurately define the effects of NNS on the gut microbiota.

Effect of food additives on key bacterial taxa and the mucosa-associated microbiota in Crohn's disease. The ENIGMA study

Food additives have been linked to the pro-inflammatory microbial dysbiosis associated with Crohn's disease (CD) but the underlying ecological dynamics are unknown. Here, we examine how selection of food additives affects the growth of multiple strains of a key beneficial bacterium (Faecalibacterium prausnitzii), axenic clinical isolates of proinflammatory bacteria from CD patients (Proteus, Morganella, and Klebsiella spp.), and the consortia of mucosa-associated microbiota recovered from multiple Crohn's disease patients. Bacterial growth of the axenic isolates was evaluated using a habitat-simulating medium supplemented with either sodium sulfite, aluminum silicate, carrageenan, carboxymethylcellulose, polysorbate 80, saccharin, sucralose, or aspartame, intended to approximate concentrations found in food. The microbial consortia recovered from post-operative CD patient mucosal biopsy samples were challenged with either carboxymethylcellulose and/or polysorbate 80, and the bacterial communities compared to unchallenged consortia by 16S rRNA gene amplicon profiling. Growth of all F. prausnitzii strains was arrested when either sodium sulfite or polysorbate 80 was added to cultures at baseline or mid-exponential phase of growth, and the inhibitory effects on the Gram-negative bacteria by sodium sulfite were conditional on oxygen availability. The effects from polysorbate 80, saccharin, carrageenan, and/or carboxymethylcellulose on these bacteria were strain-specific. In addition to their direct effects on bacterial growth, polysorbate 80 and/or carboxymethylcellulose can drive profound changes in the CD mucosa-associated microbiota via niche expansion of Proteus and/or Veillonellaceae - both implicated in early Crohn's disease recurrence. These studies on the interaction of food additives with the enteric microbiota provide a basis for dietary management in Crohn's disease.

Daily Variability in Urinary Artificial Sweeteners and Its Association with Oxidative Stress Biomarkers

Urinary artificial sweeteners (ASs) have been proved to be useful biomarkers for assessing their dietary intakes; however, it is unclear how well a spot urine sample may represent a longer-term exposure. Therefore, a longitudinal study was designed and six ASs and two oxidative stress biomarkers, namely, 8-hydroxy-2'-deoxyguanosine (8-OHdG) and malondialdehyde (MDA), were determined. Acesulfame (ACE) and saccharin (SAC) were detected in most urines with concentration ranges of Collapse

Key Words

• artificial sweeteners
• exposure assessment
• human biomonitoring
• oxidative stress biomarkers
• variability

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MESH Headings

• Humans
• 8-Hydroxy-2'-Deoxyguanosine
• Biomarkers/urine
• Deoxyguanosine
• Longitudinal Studies
• Oxidative Stress
• Saccharin
• Sweetening Agents

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Affiliation(s)

Yumeng Shi MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
Hongkai Zhu MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
Fei Wang Tianjin Key Laboratory of Clean Energy and Pollution Control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China
Shucong Chen MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
Ke Xu MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
Lei Wang MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
Hongwen Sun MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China

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Artificially Sweetened Beverage Consumption and Cancer Risk: A Comprehensive Dose-Response Meta-Analysis of Prospective Studies

The impact of artificially sweetened beverages (ASBs), alternatives to sugar-sweetened beverages, on cancer incidence remains controversial. We conducted a meta-analysis of prospective studies to assess the association of daily ASB intake with cancer risk. A systematic search was performed between January 1967 and September 2022. Risk ratios (RR) or hazard ratios (HR) were extracted and pooled. The Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach was used for the assessment of the certainty of evidence. The study was registered at PROSPERO (CRD42022312171). Overall, 14 articles with 17 cohorts were included. There was no significant association between daily ASB consumption and risk of overall cancer (highest versus lowest category: n = 17, RR = 1.03, 95% CI: 0.96-1.11, p = 0.407). For site-specific cancer analysis, the risk of non-lymphoid leukemia was elevated with high ASB intake (n = 3, RR = 1.35, 95% CI: 1.03-1.77, p = 0.030), while risk of colorectal cancer was decreased (n = 3, RR = 0.78, 95% CI: 0.62-0.99, p = 0.037). Dose-response analysis indicated a positive linear association between ASB intake and the risk of leukemia (p_-linear = 0.027). The risk increased by 15% per one serving (355 mL) daily ASB intake increment (RR = 1.15, 95% CI: 1.02-1.30). In conclusion, ASB consumption might be positively associated with the risk of leukemia and negatively associated with the risk of colorectal cancer.

Replacement of refined sugar by natural sweeteners: focus on potential health benefits

Refined sugar is a processed product containing 99% sucrose, which is obtained from sugarcane (70%) or sugar beet (30%). In modern societies, sugar continues to play a significant role in the diet, recognised not only for its flavour and special sweetening properties but also for its role in food preservation. On the other hand, a high consumption of refined sugar is associated with non-communicable diseases and many health issues such as a high risk of dental caries, overweight and neurodevelopmental disorders in children. Alternatives like unrefined sugars have generated a lot of interest as a healthy substitute due to their nutraceutical properties. This paper is aimed to review the beneficial effects of sugar derived from natural sources and highlight health problems that could be caused by refined processed sugar. Refined sugar is frequently used in variety of items including processed foods, soft drinks or ice creams although it is considered unhealthy due to its high salt and sugar content as well as added fats and artificial coloring. Natural sugars are preferred because they have a high nutritional value and a high concentration of healthy compounds, which offset the negative effects of refined sugar. Therefore, removing refined sugar or at least reducing its consumption should be promoted as a healthier option in food choices.

Non-nutritive sweeteners and their impacts on the gut microbiome and host physiology

Non-nutritive sweeteners (NNS) are broadly incorporated into foods, especially those representing a growing share of the beverage market. NNS are viewed as a noncaloric and desirable alternative to sugar-based sweeteners and are thought to contribute to reducing overall caloric intake. While these compounds have been studied extensively and have long been considered inert, new research has presented a different view and raises new questions about the effects of NNS on human physiology. Namely, the influence on glucose responses, the gastrointestinal epithelium, and the gut microbiome. As the gut microbiome is now recognized as a major mediator of human health and perturbations to this community are generally associated with negative health trajectories or overt disease, interactions between NNS and the gut microbiome are of increasing interest to clinicians and researchers. Several NNS compounds are now hypothesized to affect human physiology by modulating the gut microbiome, though the mechanism for this action remains unclear. The purpose of this review is to discuss the history and current knowledge of NNS, their reported utility and effects on host physiology and the gut microbiome, and describes a model for investigating the underlying mechanism behind reported effects of NNS on the gut microbiome.

Food Additives Associated with Gut Microbiota Alterations in Inflammatory Bowel Disease: Friends or Enemies?

During the 21st century, the incidence and prevalence of inflammatory bowel disease (IBD) is rising globally. Despite the pathogenesis of IBD remaining largely unclear, the interactions between environmental exposure, host genetics and immune response contribute to the occurrence and development of this disease. Growing evidence implicates that food additives might be closely related to IBD, but the involved molecular mechanisms are still poorly understood. Food additives may be categorized as distinct types in accordance with their function and property, including artificial sweeteners, preservatives, food colorant, emulsifiers, stabilizers, thickeners and so on. Various kinds of food additives play a role in modifying the interaction between gut microbiota and intestinal inflammation. Therefore, this review comprehensively synthesizes the current evidence on the interplay between different food additives and gut microbiome alterations, and further elucidates the potential mechanisms of food additives–associated microbiota changes involved in IBD.

Potential Effects of Sucralose and Saccharin on Gut Microbiota: A Review

Artificial sweeteners are additives widely used in our diet. Although there is no consensus, current evidence indicates that sucralose and saccharin could influence the gut microbiota. The aim of this study was to analyze the existing scientific evidence on the effects of saccharin and sucralose consumption on gut microbiota in humans. Different databases were used with the following search terms: sweeteners, non-caloric-sweeteners, sucralose, splenda, saccharin, sugartwin, sweet’n low, microbiota, gut microbiota, humans, animal model, mice, rats, and/or in vitro studies. In vitro and animal model studies indicate a dose-dependent relationship between the intake of both sweeteners and gut microbiota affecting both diversity and composition. In humans, long-term study suggests the existence of a positive correlation between sweetener consumption and some bacterial groups; however, most short-term interventions with saccharin and sucralose, in amounts below the ADI, found no significant effect on those groups, but there seems to be a different basal microbiota-dependent response of metabolic markers. Although studies in vitro and in animal models seem to relate saccharin and sucralose consumption to changes in the gut microbiota, more long-term studies are needed in humans considering the basal microbiota of participants and their dietary and lifestyle habits in all population groups. Toxicological and basal gut microbiota effects must be included as relevant factors to evaluate food safety and nutritional consequences of non-calorie sweeteners. In humans, doses, duration of interventions, and number of subjects included in the studies are key factors to interpret the results.

Is There an Academic Bias against Low-Energy Sweeteners?

This perspective considers evidence of a common academic bias against low-energy sweeteners (LES). The core proposition is that this bias is manifested in research and reporting focused on generating and placing a negative spin on LESs, largely through selective citation, interpretation and reporting. The evidence centres on three inter-related points, which together may generate a misleading impression of the balance of evidence: (1) basic and mechanistic research on LES perpetuates “explanations” for unsubstantiated adverse effects of LES; (2) the literature on LES—particularly narrative reviews and commentaries—continually reprises hypotheses of adverse effects without acknowledging where these hypotheses have been rigorously tested and rejected; and (3) negative interpretations of the effects of LES largely rely upon selectively emphasising lower-quality research whilst ignoring or dismissing higher-quality evidence. The expert community should consider these issues in assuring scientific integrity and balance in the academic discourse on LES, and how this is translated into messages for public health and consumers.

Sweeteners Maintain Epithelial Barrier Function Through the miR-15b/RECK/MMP-9 Axis, Remodel Microbial Homeostasis, and Attenuate Dextran Sodium Sulfate-Induced Colitis in Mice

Non-nutritive sweeteners are the most widely used food additives designed to provide sweetness and reduce caloric intake. Studies have confirmed a link between sweeteners and colitis, yet supporting scientific data remain exiguous and controversial. In this study, three common sweeteners (Saccharin sodium, Stevioside, and Sucralose) in acceptable daily intake dosage were added to water in order to determine their effects on dextran sodium sulfate-induced colitis in mice. Our results show that the three sweeteners meliorate colitis to varying degrees─Saccharin exerts the most pronounced effect, followed by Stevioside and Sucralose. Intake of sweeteners alleviates colitis symptoms, alters gut microbiota, reshapes the TH17/Treg balance, protects the intestinal barrier, and reduces inflammation. Most significantly, sweeteners can enhance the abundance of Mucispirillum and Alistipes, which are conducive to colitis recovery, and upregulate the expression of E-cadherin through the miR-15b/RECK/MMP-9 axis to improve intestinal barrier integrity. Moreover, by inhibiting the MMP-9/AKT/NF-κB pathway, inflammation is relieved, as reflected in the restoration of the Th17/Treg balance. Our results link the consumption of sweeteners to the remission of colitis, which provides new scientific evidence for the safe use of sweeteners.

Studies of xenobiotic-induced gut microbiota dysbiosis: from correlation to mechanisms

Environmental chemicals can alter gut microbial community composition, known as dysbiosis. However, the gut microbiota is a highly dynamic system and its functions are still largely underexplored. Likewise, it is unclear whether xenobiotic exposure affects host health through impairing host-microbiota interactions. Answers to this question not only can lead to a more precise understanding of the toxic effects of xenobiotics but also can provide new targets for the development of new therapeutic strategies. Here, we aim to identify the major challenges in the field of microbiota-exposure research and highlight the need to exam the health effects of xenobiotic-induced gut microbiota dysbiosis in host bodies. Although the changes of gut microbiota frequently co-occur with the xenobiotic exposure, the causal relationship of xenobiotic-induced microbiota dysbiosis and diseases is rarely established. The high dynamics of the gut microbiota and the complex interactions among exposure, microbiota, and host, are the major challenges to decipher the specific health effects of microbiota dysbiosis. The next stage of study needs to combine various technologies to precisely assess the xenobiotic-induced gut microbiota perturbation and the subsequent health effects in host bodies. The exposure, gut microbiota dysbiosis, and disease outcomes have to be causally linked. Many microbiota-host interactions are established by previous studies, including signaling metabolites and response pathways in the host, which may use as start points for future research to examine the mechanistic interactions of exposure, gut microbiota, and host health. In conclusion, to precisely understand the toxicity of xenobiotics and develop microbiota-based therapies, the causal and mechanistic links of exposure and microbiota dysbiosis have to be established in the next stage study.

Fueling Gut Microbes: A Review of the Interaction between Diet, Exercise, and the Gut Microbiota in Athletes

The athlete's goal is to optimize their performance. Towards this end, nutrition has been used to improve the health of athletes' brains, bones, muscles, and cardiovascular system. However, recent research suggests that the gut and its resident microbiota may also play a role in athlete health and performance. Therefore, athletes should consider dietary strategies in the context of their potential effects on the gut microbiota, including the impact of sports-centric dietary strategies (e.g., protein supplements, carbohydrate loading) on the gut microbiota as well as the effects of gut-centric dietary strategies (e.g., probiotics, prebiotics) on performance. This review provides an overview of the interaction between diet, exercise, and the gut microbiota, focusing on dietary strategies that may impact both the gut microbiota and athletic performance. Current evidence suggests that the gut microbiota could, in theory, contribute to the effects of dietary intake on athletic performance by influencing microbial metabolite production, gastrointestinal physiology, and immune modulation. Common dietary strategies such as high protein and simple carbohydrate intake, low fiber intake, and food avoidance may adversely impact the gut microbiota and, in turn, performance. Conversely, intake of adequate dietary fiber, a variety of protein sources, and emphasis on unsaturated fats, especially omega-3 (ɷ-3) fatty acids, in addition to consumption of prebiotics, probiotics, and synbiotics, have shown promising results in optimizing athlete health and performance. Ultimately, while this is an emerging and promising area of research, more studies are needed that incorporate, control, and manipulate all 3 of these elements (i.e., diet, exercise, and gut microbiome) to provide recommendations for athletes on how to "fuel their microbes."

Chronic consumption of food-additives lead to changes via microbiota gut-brain axis

Some food additives have demonstrated to induce dysbiosis leading to the development gut and gastrointestinal diseases. In order to clarify how this dysbiosis affects the microbiota gut-brain axis, a systematic interpretative literature review is carried out in this work. This review was made in seven academic search engines using the keywords shown below. The main finding of this work is a clear link between the changes in the gut microbiota promoted by food additives and the causes that lead to many reported diseases related to chronic food additives consumption. Despite the findings, studies on the effects of food additives on microbiota are still insufficient. Therefore, this work should serve as a motivation for future research on this subject.

Artificial Sweeteners: History and New Concepts on Inflammation

Since the introduction of artificial sweeteners (AS) to the North American market in the 1950s, a growing number of epidemiological and animal studies have suggested that AS may induce changes in gut bacteria and gut wall immune reactivity, which could negatively affect individuals with or susceptible to chronic inflammatory conditions such as inflammatory bowel disease (IBD), a disorder that has been growing exponentially in westernized countries. This review summarizes the history of current FDA-approved AS and their chemical composition, metabolism, and bacterial utilization, and provides a scoping overview of the disease mechanisms associated with the induction or prevention of inflammation in IBD. We provide a general outlook on areas that have been both largely and scarcely studied, emerging concepts using silica, and describe the effects of AS on acute and chronic forms of intestinal inflammation.

Crocodylus porosus Gut Bacteria: A Possible Source of Novel Metabolites

Crocodiles are remarkable animals that have the ability to endure extremely harsh conditions and can survive up to a 100 years while being exposed to noxious agents that are detrimental to Homo sapiens. Besides their immunity, we postulate that the microbial gut flora of crocodiles may produce substances with protective effects. In this study, we isolated and characterized selected bacteria colonizing the gastrointestinal tract of Crocodylusporosus and demonstrated their inhibitory effects against three different cancerous cell lineages. Using liquid chromatography-mass spectrometry, several molecules were identified. For the first time, we report partial analyses of crocodile’s gut bacterial molecules.

Diet and the Microbiota-Gut-Brain Axis: Sowing the Seeds of Good Mental Health

Over the past decade, the gut microbiota has emerged as a key component in regulating brain processes and behavior. Diet is one of the major factors involved in shaping the gut microbiota composition across the lifespan. However, whether and how diet can affect the brain via its effects on the microbiota is only now beginning to receive attention. Several mechanisms for gut-to-brain communication have been identified, including microbial metabolites, immune, neuronal, and metabolic pathways, some of which could be prone to dietary modulation. Animal studies investigating the potential of nutritional interventions on the microbiota-gut-brain axis have led to advancements in our understanding of the role of diet in this bidirectional communication. In this review, we summarize the current state of the literature triangulating diet, microbiota, and host behavior/brain processes and discuss potential underlying mechanisms. Additionally, determinants of the responsiveness to a dietary intervention and evidence for the microbiota as an underlying modulator of the effect of diet on brain health are outlined. In particular, we emphasize the understudied use of whole-dietary approaches in this endeavor and the need for greater evidence from clinical populations. While promising results are reported, additional data, specifically from clinical cohorts, are required to provide evidence-based recommendations for the development of microbiota-targeted, whole-dietary strategies to improve brain and mental health.

An Overview of Current Knowledge of the Gut Microbiota and Low-Calorie Sweeteners

This review provides an overview of the interrelationships among the diet, gut microbiota and health status, and then focuses specifically on published research assessing the relationship of low/no-calorie sweeteners (LNCS) to selected aspects of the gut microbiota. Microbiome research is expanding as new data on its role in health and disease vulnerability emerge. The gut microbiome affects health, digestion, and susceptibility to disease. In the last 10 years, investigations of LNCS effects on the gut microbiota have proliferated, though results are conflicting and are often confounded by differences in study design such as study diet, the form of the test article, dosage, and study population. Staying current on microbiome research and the role of dietary inputs, like LNCS, will allow healthcare and nutrition practitioners to provide evidenced-based guidance to the individuals they serve.

Effects of Non-Nutritive Sweeteners on Energy Intake, Body Weight and Postprandial Glycemia in Healthy and with Altered Glycemic Response Rats

The aim of this study was to evaluate the effects of non-nutritive sweeteners (NNS) consumption on energy intake, body weight and postprandial glycemia in healthy and with altered glycemic response rats. Animals on normal diet (ND) or high-fat diet (HFD) were divided to receive NNS (sucralose, aspartame, stevia, rebaudioside A) or nutritive sweeteners (glucose, sucrose) for 8 weeks. The NNS were administered at doses equivalent to the human acceptable daily intake (ADI). A test using rapidly digestible starch was performed before and after treatments to estimate glycemic response. No effects of NNS consumption were observed on energy intake or body weight. Sucrose provoked an increased fluid consumption, however, energy intake, and weight gain were not altered. In ND, no effects of NNS on glycemic response were observed. In HFD, the glycemic response was increased after sucralose and stevia when only the final tolerance test was considered, however, after including the baseline test, these results were no longer significant compared to glucose. These findings provide further evidence suggesting that at the recommended doses, NNS do not alter feeding behavior, body weight or glycemic tolerance in healthy and with altered glycemic rats.

Soft drinks and sweeteners intake: Possible contribution to the development of metabolic syndrome and cardiovascular diseases. Beneficial or detrimental action of alternative sweeteners?

The rapid increase in obesity, metabolic syndrome, and cardiovascular diseases (CVDs) has been related to the rise in sugar-added foods and sweetened beverages consumption. An interesting approach has been to replace sugar with alternative sweeteners (AS), due to their impact on public health. Preclinical and clinical studies, which analyze the safety of AS intake, are still limited. Major pathogenic mechanisms of these substances include ROS and AGEs formation. Indeed, endothelial dysfunction involving in the pathogenesis of micro- and macro-vascular diseases is mitochondrial dysfunction dependent. Hyperglycemia and endoplasmic reticulum stress together produce ROS, contributing to the development and progression of cardiovascular complications during type 2 diabetes (T2D), thus causing oxidative changes and direct damage of lipids, proteins, and DNA. Epidemiological studies in healthy subjects have suggested that the consumption of artificial AS can promote CV complications, such as glucose intolerance and predisposition to the onset of T2D, whereas natural AS could reduce hyperglycemia, improve lipid metabolism and have antioxidant effects. Long-term prospective clinical randomized studies are needed to evaluate precisely whether exposure to alternative sugars can have clinical implications on natural history and clinical outcomes, especially in children or during the gestational period through breast milk.

Low-calorie sweeteners in the human diet: scientific evidence, recommendations, challenges and future needs. A symposium report from the FENS 2019 conference

Overconsumption of free sugars, particularly from sugar-sweetened beverages (SSB), has potential negative health impacts. Implementation of a range of public health strategies is needed to reduce intakes of free sugars, including reducing portion sizes, promoting healthier dietary choices and reformulating foods and beverages. Although low-calorie sweeteners (LCS) are a useful tool for reducing energy intake and control glucose response when consuming sweet foods and drinks, several opinions persist about the adverse health effects of LCS, many of which are based on poor, little or no scientific evidence. This symposium report summarises key messages of the presentations and related discussions delivered at a scientific symposium at the 13th European Nutrition Conference (FENS 2019). These presentations considered the scientific evidence and current recommendations about the use and potential benefits of LCS for human health, with a particular focus on current evidence in relation to body weight and glycaemic control. Many of the studies to date on LCS have focused on low-calorie sweetened beverages (LCSB); however, the psychological and behavioural factors influencing consumer beliefs and consumption of LCSB need to be further explored. Current recommendations for LCS use are described, including the conclusions from a recent expert consensus report identifying the challenges that remain with LCS research. Finally, existing knowledge gaps and future actions are described, as well as two large ongoing research projects: SWITCH and SWEET.

PREVALENCE OF HEARING SYMPTOMS RELATED TO PATULOUS EUSTACHIAN TUBE AFTER BARIATRIC SURGERY

Background:

Rapid and severe weight loss can result in the reduction of the ear tube lining fat tissue and it becomes patent, leading to symptoms such as autophony, aural fullness and tinnitus. Patients after bariatric surgery have, in theory, a predisposition to the development of such alteration.

Aim:

To evaluate the presence of patent tuba-related complaints in patients undergoing bariatric surgery, correlating with weight and body mass index (BMI) values, as well as demographic data.

Methods:

Cross-sectional study composed of the evaluation of patients undergoing bariatric surgery through a standardized questionnaire about the presence of symptoms compatible with ear tube patency.

Results:

Eighty patients were evaluated, 77 female and three males. The main comorbidity was systemic arterial hypertension (37.5%). Fifteen (18.75%) presented symptoms compatible with patent auditory/Eustachian tube - aural fullness and autophony - postoperatively. In symptomatic individuals the initial weight was 112 kg on average and the preoperative BMI was 45 kg/m², while in asymptomatic individuals the weight was 117 kg and BMI 47 kg/m². There was statistical significance in the comparison between individuals with and without symptoms in the variables of initial weight (p=0.00000), current weight (p=0.00029), preoperative BMI (p=0.00219) and postoperative BMI (p=0.00148).

Conclusion:

The presence of symptoms compatible with patent auditory/Eustachian tube was 18.75% of the patients submitted to bariatric surgery in the evaluated sample. Both preoperative weight and BMI were lower in symptomatic patients when compared with the asymptomatic group.

High Concentrations of Aspartame Induce Pro-Angiogenic Effects in Ovo and Cytotoxic Effects in HT-29 Human Colorectal Carcinoma Cells

Aspartame (ASP), an artificial sweetener abundantly consumed in recent years in an array of dietary products, has raised some concerns in terms of toxicity, and it was even suggested a link with the risk of carcinogenesis (colorectal cancer), though the present scientific data are rather inconclusive. This study aims at investigating the potential role of aspartame in colorectal cancer by suggesting two experimental approaches: (i) an in vitro cytotoxicity screening in HT-29 human colorectal carcinoma cells based on cell viability (Alamar blue assay), cell morphology and cell migration (scratch assay) assessment and (ii) an in ovo evaluation in terms of angiogenic and irritant potential by means of the chorioallantoic membrane method (CAM). The in vitro results showed a dose-dependent cytotoxic effect, with a significant decrease of viable cells at the highest concentrations tested (15, 30 and 50 mM) and morphological cellular changes. In ovo, aspartame (15 and 30 mM) proved to have a pro-angiogenic effect and a weak irritant potential at the vascular level. These data suggest new directions of research regarding aspartame’s role in colorectal cancer.

Mediterranean Diet Adherence and Dietary Attitudes in Patients with Inflammatory Bowel Disease

A specific diet regimen is a promising way of managing inflammatory bowel disease (IBD), with the Mediterranean diet (MD) being a likely candidate due to its potential to modulate gut inflammation. Therefore, the aim of this study was to investigate nutritional habits and dietary attitudes of IBD patients, and to assess their adherence to the Mediterranean diet. The study enrolled 50 Crohn’s disease and 44 ulcerative colitis patients, with clinical and laboratory parameters taken. Dietary attitudes were examined, and adherence to MD was assessed using the Mediterranean Diet Service Score (MDSS). Average MDSS score was 6.0 (5.0–7.0), while only nine participants fulfilled criteria for Mediterranean diet adherence. Moreover, all of them were men (p = 0.021). Low percentage of adherence to recommended guidelines was observed for eating olive oil (25.5%), fresh fruit (14.9%), and vegetables (10.6%). Significant positive correlation was observed between total MDSS points and high-density lipoprotein (HDL) cholesterol levels (p = 0.002). The majority of the patients (86.2%) considered that a more controlled diet could reduce their IBD symptoms, while 17% visited a nutritionist for diet advice. The majority of patients (84%) would visit educational programs regarding nutrition. In conclusion, adherence to MD was very low, while IBD patients were willing to extend their nutritional knowledge if proper educational programs were organized.

Non-Alcoholic Beverages, Old and Novel, and Their Potential Effects on Human Health, with a Focus on Hydration and Cardiometabolic Health

The Beverage Guidance System has established dietary recommendations for daily intake of commonly consumed beverages including water, tea, coffee, milk, non-calorically sweetened beverages, and calorically sweetened beverages. As obesity in America continues to be a growing problem, this guidance becomes of increasing importance due to many beverages' potential links to Type 2 Diabetes Mellitus (T2DM), Cardiovascular disease (CVD), and numerous other harmful health effects. However, the growing popularity of "better for you" beverages is causing a shift in the market, with consumers pushing for healthier beverage alternatives. Beverages simultaneously present advantages while posing concerns that need to be evaluated and considered. In this review, health effects of nonalcoholic beverages are discussed including various aspects of consumption and current trends of the beverage market such as the novel Soft Seltzer category as an alternative to Hard Seltzer and various mashups. A variety of advisory boards and agencies responsible for dietary guidelines in various countries suggest drinking water as the preferred practice for hydration.

Periodic Revisions of the International Choices Criteria: Process and Results

Unhealthy diets contribute to an increased risk of non-communicable diseases, which are the leading causes of deaths worldwide. Nutrition policies such as front-of-pack labeling have been developed and implemented globally in different countries to stimulate healthier diets. The Choices Programme, including the International Choices criteria, is an established tool to support the implementation of such policies. The Choices criteria were developed to define the healthier choices per product group, taking saturated fatty acids, trans fatty acids, sodium, sugars, energy, and fiber into account. To keep these criteria updated, they are periodically revised by an independent international scientific committee. This paper explains the most important changes resulting from revisions between 2010 and 2016 and describes the process of the latest revision, resulting in the International Choices criteria version 2019. Revisions were based on national and international nutrition and dietary recommendations, large food composition databases, and stakeholders' feedback. Other nutrient profiling systems served as benchmarks. The product group classification was adapted and new criteria were determined in order to enhance global applicability and form a credible, intuitively logical system for users. These newly developed criteria will serve as an international standard for healthier products and provide a guiding framework for food and nutrition policies.

EFFECTS OF PROBIOTICS SUPPLEMENTATION ON SKIN WOUND HEALING IN DIABETIC RATS

Background:

Chronic wounds in patients with Diabetes Mellitus often become incurable due to prolonged and excessive production of inflammatory cytokines. The use of probiotics modifies the intestinal microbiota and modulates inflammatory reactions.

Aim:

To evaluate the influence of perioperative supplementation with probiotics in the cutaneous healing process in diabetic rats.

Methods:

Forty-six rats were divided into four groups (C3, P3, C10, P10) according to the treatment (P=probiotic or C=control, both orally administered) and day of euthanasia, 3^rd or 10^th postoperative days. All rats were induced to Diabetes Mellitus 72 h before starting the experiment with alloxan. Supplementation was initiated five days before the incision and maintained until euthanasia. Scalpel incision was guided by a 2x2 cm mold and the wounds were left to heal per second-intention. The wounds were digitally measured. Collagen densitometry was done with Picrosirius Red staining. Histological parameters were analyzed by staining by H&E.

Results:

The contraction of the wound was faster in the P10 group which resulted in a smaller scar area (p=0.011). There was an increase in type I collagen deposition from the 3^rd to the 10^th postoperative day in the probiotic groups (p=0.016), which did not occur in the control group (p=0.487). The histological analysis showed a better degree of healing in the P10 group (p=0.005), with fewer polymorphonuclear (p<0.001) and more neovessels (p=0.001).

Conclusions:

Perioperative supplementation of probiotics stimulates skin wound healing in diabetic rats, possibly due to attenuation of the inflammatory response and increased neovascularization and type I collagen deposition.

Intake of Sugar-Sweetened and Low-Calorie Sweetened Beverages and Risk of Cardiovascular Disease: A Meta-Analysis and Systematic Review

The long-term associations between the consumption of sugar-sweetened beverages (SSBs) and low-calorie sweetened beverages (LCSBs) with cardiovascular diseases (CVDs) remains inconsistent. To synthesize the evidence, we conducted a meta-analysis of prospective cohort studies published up to 1 December, 2019 on the associations between SSB and LCSB intake and the risk of CVD incidence and mortality. Out of 5301 articles retrieved from our literature search, 11 articles evaluating the consumption of SSBs (16,915 incident CVD cases, 18,042 CVD deaths) and 8 articles evaluating the consumption of LCSBs (18,077 incident CVD cases, 14,114 CVD deaths) were included in the meta-analysis. A 1 serving/d increment of SSBs was associated with an 8% (RR: 1.08; 95% CI: 1.02, 1.14, I2 = 43.0%) and 8% (RR: 1.08; 95% CI: 1.04, 1.13, I2 = 40.6%) higher risk of CVD incidence and CVD mortality, respectively. A 1 serving/d increment of LCSBs was associated with a 7% (RR: 1.07; 95% CI: 1.05, 1.10, I2 = 0.0%) higher risk of CVD incidence. The association between LCSBs and CVD mortality appeared to be nonlinear (P = 0.003 for nonlinearity) with significant associations observed at high intake levels (>2 servings/d). Under an assumption of causality, the consumption of SSBs may be linked to 9.3% (95% CI: 6.6%, 11.9%) of predicted CVD incidence in the USA from 2015 to 2025, among men and nonpregnant women, who were aged 40-79 y in 2015-2016. The habitual consumption of SSBs was associated with a higher risk of CVD morbidity and mortality in a dose-response manner. LCSBs were also associated with a higher risk of these outcomes, however, the interpretation of these findings may be complicated by reverse causation and residual confounding.

Expert consensus on low-calorie sweeteners: facts, research gaps and suggested actions

A consensus workshop on low-calorie sweeteners (LCS) was held in November 2018 where seventeen experts (the panel) discussed three themes identified as key to the science and policy of LCS: (1) weight management and glucose control; (2) consumption, safety and perception; (3) nutrition policy. The aims were to identify the reliable facts on LCS, suggest research gaps and propose future actions. The panel agreed that the safety of LCS is demonstrated by a substantial body of evidence reviewed by regulatory experts and current levels of consumption, even for high users, are within agreed safety margins. However, better risk communication is needed. More emphasis is required on the role of LCS in helping individuals reduce their sugar and energy intake, which is a public health priority. Based on reviews of clinical evidence to date, the panel concluded that LCS can be beneficial for weight management when they are used to replace sugar in products consumed in the diet (without energy substitution). The available evidence suggests no grounds for concerns about adverse effects of LCS on sweet preference, appetite or glucose control; indeed, LCS may improve diabetic control and dietary compliance. Regarding effects on the human gut microbiota, data are limited and do not provide adequate evidence that LCS affect gut health at doses relevant to human use. The panel identified research priorities, including collation of the totality of evidence on LCS and body weight control, monitoring and modelling of LCS intakes, impacts on sugar reduction and diet quality and developing effective communication strategies to foster informed choice. There is also a need to reconcile policy discrepancies between organisations and reduce regulatory hurdles that impede low-energy product development and reformulation.

Perspective: Standards for Research and Reporting on Low-Energy ("Artificial") Sweeteners

Widely differing views exist among experts, policy makers, and the general public with regard to the potential risks and benefits of reduced- or low-energy sweeteners (LES) in the diet. These views are informed and influenced by different types of research in LES, with differing hypotheses, designs, interpretation, and communication. Given the high level of interest in LES, and the public health relevance of the research evidence base, it is important that all aspects of the research process are framed and reported in an appropriate and balanced manner. In this Perspective, we identify and give examples of a number of issues relating to research and reviews on LES, which may contribute toward apparent inconsistencies in the content and understanding of the totality of evidence. We conclude with a set of recommendations for authors, reviewers and journal editors, as general guidance to improve and better standardize the quality of LES research design, interpretation, and reporting. These focus on clarity of underlying hypotheses, characterization of exposures, and the placement and weighting of new research within the wider context of related prior work.

Plausible Biological Interactions of Low- and Non-Calorie Sweeteners with the Intestinal Microbiota: An Update of Recent Studies

Sweeteners that are a hundred thousand times sweeter than sucrose are being consumed as sugar substitutes. The effects of sweeteners on gut microbiota composition have not been completely elucidated yet, and numerous gaps related to the effects of nonnutritive sweeteners (NNS) on health still remain. The NNS aspartame and acesulfame-K do not interact with the colonic microbiota, and, as a result, potentially expected shifts in the gut microbiota are relatively limited, although acesulfame-K intake increases Firmicutes and depletes Akkermansia muciniphila populations. On the other hand, saccharin and sucralose provoke changes in the gut microbiota populations, while no health effects, either positive or negative, have been described; hence, further studies are needed to clarify these observations. Steviol glycosides might directly interact with the intestinal microbiota and need bacteria for their metabolization, thus they could potentially alter the bacterial population. Finally, the effects of polyols, which are sugar alcohols that can reach the colonic microbiota, are not completely understood; polyols have some prebiotics properties, with laxative effects, especially in patients with inflammatory bowel syndrome. In this review, we aimed to update the current evidence about sweeteners' effects on and their plausible biological interactions with the gut microbiota.

Metabarcoding reveals that a non-nutritive sweetener and sucrose yield similar gut microbiota patterns in Wistar rats

The effects of non-nutritive sweeteners (NNS) on the gut microbiota are an area of increasing research interest due to their potential influence on weight gain, insulin resistance, and inflammation. Studies have shown that mice and rats fed saccharin develop weight gain and metabolic alterations, possibly related to changes in gut microbiota. Here, we hypothesized that chronic exposure to a commercial NNS would change the gut microbiota composition in Wistar rats when compared to sucrose exposure. To test this hypothesis, Wistar rats were fed either NNS- or sucrose-supplemented yogurt for 17 weeks alongside standard chow (ad libitum). The gut microbiome was assessed by 16S rDNA deep sequencing. Assembly and quantification were conducted using the Brazilian Microbiome Project pipeline for Ion Torrent data with modifications. Statistical analyses were performed in the R software environment. We found that chronic feeding of a commercial NNS-sweetened yogurt to Wistar rats, within the recommended dose range, did not significantly modify gut microbiota composition in comparison to sucrose-sweetened yogurt. Our findings do not support the hypothesis that moderate exposure to NNS is associated with changes in gut microbiota pattern compared to sucrose, at least in this experimental model.

Nonalcoholic fatty liver disease, insulin resistance, and sweeteners: a literature review

Introduction: Sweeteners are substances used to replace sugar. They can either be chemically produced (artificial sweeteners) or extracted from plants (natural sweeteners). In the last two decades, there is an increased popularity in their role as sugar substitutes in individuals to promote weight loss or maintain glycemic control. However, despite their favorable effects, there is concern regarding their side effects and especially their influence in the development of nonalcoholic fatty liver disease (NAFLD).Areas covered: A comprehensive literature search was conducted on Medline including systematic reviews, longitudinal controlled studies, and retrospective cohort studies. We present an up-to-date systematic review of the current literature regarding the safety in artificial and natural sweeteners use as a means of weight loss or diabetes control.Expert opinion: Natural sweeteners have not been associated directly with NAFLD, and on the contrary, some, such as stevia, and trehalose, may have a protective effect. Rare sugars and polyols can be used safely and have significant benefits that include anti-oxidant effect and optimal glycemic control. Artificial sweeteners, due to their effect on NAFLD development and insulin resistance, are not indicated in patients with obesity or diabetes. Further studies in human subjects are required to verify the above findings.

Low Calorie Sweeteners Differ in Their Physiological Effects in Humans

Low calorie sweeteners (LCS) are prevalent in the food supply for their primary functional property of providing sweetness with little or no energy. Though tested for safety individually, there has been extremely limited work on the efficacy of each LCS. It is commonly assumed all LCS act similarly in their behavioral and physiological effects. However, each LCS has its own chemical structure that influences its metabolism, making each LCS unique in its potential effects on body weight, energy intake, and appetite. LCS may have different behavioral and physiological effects mediated at the sweet taste receptor, in brain activation, with gut hormones, at the microbiota and on appetitive responses. Further elucidation of the unique effects of the different commercially available LCS may hold important implications for recommendations about their use for different health outcomes.

Short-term impact of sucralose consumption on the metabolic response and gut microbiome of healthy adults

Sucralose is an artificial non-nutritive sweetener used in foods aimed to reduce sugar and energy intake. While thought to be inert, the impact of sucralose on metabolic control has shown to be the opposite. The gut microbiome has emerged as a factor shaping metabolic responses after sweetener consumption. We examined the short-term effect of sucralose consumption on glucose homeostasis and gut microbiome of healthy male volunteers. We performed a randomised, double-blind study in thirty-four subjects divided into two groups, one that was administered sucralose capsules (780 mg/d for 7 d; n 17) and a control group receiving placebo (n 17). Before and after the intervention, glycaemic and insulinaemic responses were assessed with a standard oral glucose load (75 g). Insulin resistance was determined using homeostasis model assessment of insulin resistance and Matsuda indexes. The gut microbiome was evaluated before and after the intervention by 16S rRNA sequencing. During the study, body weight remained constant in both groups. Glycaemic control and insulin resistance were not affected during the 7-d period. At the phylum level, gut microbiome was not modified in any group. We classified subjects according to their change in insulinaemia after the intervention, to compare the microbiome of responders and non-responders. Independent of consuming sucralose or placebo, individuals with a higher insulinaemic response after the intervention had lower Bacteroidetes and higher Firmicutes abundances. In conclusion, consumption of high doses of sucralose for 7 d does not alter glycaemic control, insulin resistance, or gut microbiome in healthy individuals. However, it highlights the need to address individual responses to sucralose.