Low-no-calorie sweeteners exert marked compound-specific impact on the human gut microbiota ex vivo

Re-evaluation of acesulfame K (E 950) as food additive

The present opinion deals with the re-evaluation of acesulfame K (E 950) as a food additive. Acesulfame K (E 950) is the chemically manufactured compound 6-methyl-1,2,3-oxathiazin-4(3H)-one-2,2-dioxide potassium salt. It is authorised for use in the European Union (EU) in accordance with Regulation (EC) No 1333/2008. The assessment involved a comprehensive review of existing authorisations, evaluations and new scientific data. Acesulfame K (E 950) was found to be stable under various conditions; at pH lower than 3 with increasing temperatures, it is degraded to a certain amount. Based on the available data, no safety concerns arise for genotoxicity of acesulfame K (E 950) and its degradation products. For the potential impurities, based on in silico data, a concern for genotoxicity was identified for 5-chloro-acesulfame; a maximum limit of 0.1 mg/kg, or alternatively, a request for appropriate genotoxicity data was recommended. Based on the synthesis of systematically appraised evidence of human and animal studies, the Panel concluded that there are no new studies suitable for identification of a reference point (RP) on adverse effects. Consequently, the Panel established an acceptable daily intake (ADI) of 15 mg/kg body weight (bw) per day based on the highest dose tested without adverse effects in a chronic toxicity and carcinogenicity study in rats; a study considered of moderate risk of bias and one of two key studies from the previous evaluations by the Scientific Committee on Food (SCF) and the Joint FAO/WHO Expert Committee on Food Additives (JECFA). This revised ADI replaces the ADI of 9 mg/kg bw per day established by the SCF. The Panel noted that the highest estimate of exposure to acesulfame K (E 950) was generally below the ADI in all population groups. The Panel recommended the European Commission to consider the revision of the EU specifications of acesulfame K (E 950).

Impacts of non-nutritive sweeteners on the human microbiome

Replacing sugar with non-nutritive sweeteners (NNS) is a common dietary strategy for reducing the caloric content and glycemic index of foods and beverages. However, the efficacy of this strategy in preventing and managing metabolic syndrome and its associated comorbidities remains uncertain. Human cohort studies suggest that NNS contribute to, rather than prevent, metabolic syndrome, whereas randomized controlled trials yield heterogeneous outcomes, ranging from beneficial to detrimental impacts on cardiometabolic health. The World Health Organization recently issued a conditional recommendation against using NNS, citing the need for additional evidence causally linking sweeteners to health effects. One proposed mechanism through which NNS induce metabolic derangements is through disruption of the gut microbiome, a link strongly supported by evidence in preclinical models. This review summarizes the evidence for similar effects in interventional and observational trials in humans. The limited available data highlight heterogeneity between trials, as some, but not all, find NNS consumption associated with microbiome modulation as well as metabolic effects independent of sweetener type. In other trials, the lack of microbiome changes coincides with the absence of metabolic effects. We discuss the hypothesis that the impacts of NNS on health are personalized and microbiome dependent. Thus, a precision nutrition approach may help resolve the conflicting reports regarding NNS impacts on the microbiome and health. This review also discusses additional factors contributing to study heterogeneity that should be addressed in future clinical trials to clarify the relationship between NNS, the microbiome, and health to better inform dietary guidelines and public health policies.

Effects of D-Tagatose on Cariogenic Risk: A Systematic Review of Randomized Clinical Trials

Dental caries remains a prevalent chronic disease driven by dysbiosis in the oral biofilm, with Streptococcus mutans playing a central role in its pathogenesis.

OBJECTIVE

This study aimed to assess the effect of D-tagatose on cariogenic risk by analyzing randomized clinical trials (RCTs).

METHODS

A systematic literature review was conducted targeting RCTs published up to 2024 in eight databases and two gray literature sources. The search strategy utilized Medical Subject Headings (MeSHs) and relevant keywords combined via Boolean operators using the query "Tagatose OR D-tagatose AND Dental Caries". Eligible studies must evaluate the impact of D-tagatose on cariogenic risk, as indicated by reductions in colony-forming units (CFUs) and improvements in salivary pH levels in treatment groups.

RESULTS

From 1139 retrieved records, three studies met the inclusion criteria. These studies consistently demonstrated significant reductions in CFU counts and improvements in salivary pH levels in groups treated with D-tagatose compared to controls using other non-caloric sweeteners or placebos (p < 0.01). However, the quality of the evidence was heterogeneous, with certain methodological concerns.

CONCLUSIONS

Although the findings suggest potential benefits of D-tagatose in reducing cariogenic risk, limitations such as small sample sizes and variability in study methodologies warrant caution. Further robust investigations are needed to substantiate these promising results and support the integration of D-tagatose into oral care formulations aimed at reducing cariogenic risk.

Carrot-Derived Rhamnogalacturonan-I Consistently Increases the Microbial Production of Health-Promoting Indole-3-Propionic Acid Ex Vivo

BACKGROUND

Using dietary interventions to steer the metabolic output of the gut microbiota towards specific health-promoting metabolites is often challenging due to interpersonal variation in treatment responses.

METHODS

In this study, we combined the ex vivo SIFR® (Systemic Intestinal Fermentation Research) technology with untargeted metabolite profiling to investigate the impact of carrot-derived rhamnogalacturonan-I (cRG-I) on ex vivo metabolite production by the gut microbiota of 24 human adults.

RESULTS

The findings reveal that at a dose equivalent to 1.5 g/d, cRG-I consistently promoted indole-3-propionic acid (IPA) production (+45.8% increase) across all subjects. At a dose equivalent to 0.3 g/d, increased IPA production was also observed (+14.6%), which was comparable to the effect seen for 1.5 g/d inulin (10.6%). IPA has been shown to provide protection against diseases affecting the gut and multiple organs. The Pearson correlation analysis revealed a strong correlation (R = 0.65, padjusted = 6.1 × 10-16) between the increases in IPA levels and the absolute levels of Bifidobacterium longum, a producer of indole-3-lactic acid (ILA), an intermediate in IPA production. Finally, the community modulation score, a novel diversity index, demonstrated that cRG-I maintained a high α-diversity which has previously been linked to elevated IPA production.

CONCLUSIONS

The results from the ex vivo SIFR® experiment mirrored clinical outcomes and provided novel insights into the impact of cRG-I on the gut microbiome function. Importantly, we demonstrated that cRG-I promotes tryptophan conversion into IPA via gut microbiome modulation, thus conferring benefits via amino acid derived metabolites extending beyond those previously reported for short chain fatty acids (SCFA) resulting from carbohydrate fermentation.

Artificial sweetener-induced dysbiosis and associated molecular signatures

Despite their approval for inclusion in beverages, and food products, the safety of artificial sweeteners is still a topic of debate within the scientific community. A significant aspect of this debate focuses on the potential of artificial sweeteners to induce dysbiosis, an imbalance in the intestinal microbiota, which has been associated with many diseases including obesity, Type 2 diabetes, and cardiovascular diseases. The interactions and mechanisms of action of artificial sweeteners within the gut microbiota, as well as the extent of associated molecular alterations, are still under active investigation. This review aims to evaluate recent developments in artificial sweetener-induced dysbiosis with its associated molecular signatures. Importantly, potential future directions for research are proposed, offering insights that could guide further targeted studies and inform dietary recommendations and policy revisions.

Impacts of food additives on gut microbiota and host health

The rapidly expanding food industry necessitates the use of food additives to achieve specific purposes. However, this raises new concerns in food safety due to the reported negative impacts of food additives on gut microbiota and host health, particularly in the context of continuous worldwide urbanization. This review summarizes the existing studies on the effects of different types of commonly used food additives on gut microbiota alteration, intestinal barrier disruption, metabolism disorder, and neurobehavior changes. These food additives, including emulsifiers, low-calorie sweeteners, inorganic nanoparticles, and preservatives, have been found to exert multifaceted impacts, primarily adverse effects, highlighting the potential risks associated with food additive exposure in various chronic diseases. Further research is warranted to elucidate the specific mechanisms, determine the relevance of these findings to humans, and clarify the suitability of certain food additives for vulnerable populations. It is crucial to note that natural food additives are not inherently superior to synthetic ones in terms of safety. Rigorous evaluation is still warranted before their widespread application in the food industry. Additionally, the potential synergistic effects of commonly used food additives combination in specific food categories on gut microbiota and host metabolism should be investigated to understand their relevance in real-world scenarios.

The key to intestinal health: a review and perspective on food additives

In this review, we explore the effects of food additives on intestinal health. Food additives, such as preservatives, antioxidants and colorants, are widely used to improve food quality and extend shelf life. However, their effects on intestinal microecology May pose health risks. Starting from the basic functions of food additives and the importance of intestinal microecology, we analyze in detail how additives affect the diversity of intestinal flora, oxidative stress and immune responses. Additionally, we examine the association between food additives and intestinal disorders, including inflammatory bowel disease and irritable bowel syndrome, and how the timing, dosage, and individual differences affect the body's response to additives. We also assess the safety and regulatory policies of food additives and explore the potential of natural additives. Finally, we propose future research directions, emphasizing the refinement of risk assessment methods and the creation of safer, innovative additives.

Functional Muffins Exert Bifidogenic Effects along with Highly Product-Specific Effects on the Human Gut Microbiota Ex Vivo

GoodBiome™ Foods are functional foods containing a probiotic (Bacillus subtilis HU58™) and prebiotics (mainly inulin). Their effects on the human gut microbiota were assessed using ex vivo SIFR® technology, which has been validated to provide clinically predictive insights. GoodBiome™ Foods (BBM/LCM/OSM) were subjected to oral, gastric, and small intestinal digestion/absorption, after which their impact on the gut microbiome of four adults was assessed (n = 3). All GoodBiome™ Foods boosted health-related SCFA acetate (+13.1/14.1/13.8 mM for BBM/LCM/OSM), propionate (particularly OSM; +7.4/7.5/8.9 mM for BBM/LCM/OSM) and butyrate (particularly BBM; +2.6/2.1/1.4 mM for BBM/LCM/OSM). This is related to the increase in Bifidobacterium species (B. catenulatum, B. adolescentis, B. pseudocatenulatum), Coprococcus catus and Bacteroidetes members (Bacteroides caccae, Phocaeicola dorei, P. massiliensis), likely mediated via inulin. Further, the potent propionogenic potential of OSM related to increased Bacteroidetes members known to ferment oats (s key ingredient of OSM), while the butyrogenic potential of BBM related to a specific increase in Anaerobutyricum hallii, a butyrate producer specialized in the fermentation of erythritol (key ingredient of BBM). In addition, OSM/BBM suppressed the pathogen Clostridioides difficile, potentially due to inclusion of HU58™ in GoodBiome™ Foods. Finally, all products enhanced a spectrum of metabolites well beyond SCFA, including vitamins (B3/B6), essential amino acids, and health-related metabolites such as indole-3-propionic acid. Overall, the addition of specific ingredients to complex foods was shown to specifically modulate the gut microbiome, potentially contributing to health benefits. Noticeably, our findings contradict a recent in vitro study, underscoring the critical role of employing a physiologically relevant digestion/absorption procedure for a more accurate evaluation of the microbiome-modulating potential of complex foods.

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.

Serum-Derived Bovine Immunoglobulin Promotes Barrier Integrity and Lowers Inflammation for 24 Human Adults Ex Vivo

Serum-derived bovine immunoglobulin (SBI) prevents translocation and inflammation via direct binding of microbial components. Recently, SBI also displayed potential benefits through gut microbiome modulation. To confirm and expand upon these preliminary findings, SBI digestion and colonic fermentation were investigated using the clinically predictive ex vivo SIFR® technology (for 24 human adults) that was, for the first time, combined with host cells (epithelial/immune (Caco-2/THP-1) cells). SBI (human equivalent dose (HED) = 2 and 5 g/day) and the reference prebiotic inulin (IN; HED = 2 g/day) significantly promoted gut barrier integrity and did so more profoundly than a dietary protein (DP), especially upon LPS-induced inflammation. SBI also specifically lowered inflammatory markers (TNF-α and CXCL10). SBI and IN both enhanced SCFA (acetate/propionate/butyrate) via specific gut microbes, while SBI specifically stimulated valerate/bCFA and indole-3-propionic acid (health-promoting tryptophan metabolite). Finally, owing to the high-powered cohort (n = 24), treatment effects could be stratified based on initial microbiota composition: IN exclusively stimulated (acetate/non-gas producing) Bifidobacteriaceae for subjects classifying as Bacteroides/Firmicutes-enterotype donors, coinciding with high acetate/low gas production and thus likely better tolerability of IN. Altogether, this study strongly suggests gut microbiome modulation as a mechanism by which SBI promotes health. Moreover, the SIFR® technology was shown to be a powerful tool to stratify treatment responses and support future personalized nutrition approaches.

Gastrointestinal tolerance of D-allulose in children: an acute, randomised, double-blind, placebo-controlled, cross-over study

D-Allulose, a low-calorie sugar, provides an attractive alternative to added sugars in food and beverage products. There is however limited data on its gastrointestinal (GI) tolerance, with only two studies in adults, and no studies in children to date. We therefore performed an acute, randomised, double-blind, placebo-controlled, cross over study designed to determine, for the first time, the GI tolerance of 2 doses of D-allulose (2.5 g per 120 ml and 4.3 g per 120 ml) in young children. The primary tolerance endpoint was the difference in the number of participants experiencing at least one stool that met a Type 6 or Type 7 description on the Bristol Stool Chart, within 24 hours after study product intake. Secondary endpoints included the assessment of stool frequency, stool consistency, and the presence of GI symptoms. Only one participant in the low dose group experienced a stool type 6 or 7, while no participants experienced a stool type 6 or 7 in the high dose group. A statistically significant difference in the change in stool frequency compared to placebo in the high dose group (p = 0.044) was found, with no significant difference between the groups for stool consistency and no participants experienced unusual stool frequency. All the encountered adverse events were non-serious, either mild or moderate, and there were no serious adverse events. All in all, D-allulose was tolerated well in children, making this ingredient a good candidate to reformulate commercially produced goods by replacing added sugars with lower caloric content.