Food Emulsifiers and Metabolic Syndrome: The Role of the Gut Microbiota

Association between higher consumption of ultra-processed foods and risk of diabetes and its complications: A systematic review & updated meta-analysis

BACKGROUND & AIMS

Recent epidemiologic studies on the association between higher consumption of ultra-processed foods (UPFs) and risk of incident diabetes have reported conflicting results in populations worldwide. We conducted an updated systematic review and meta-analysis to quantify the magnitude of this association.

METHODS

PubMed and Embase databases were systematically searched (from 2009 to November 14, 2024) for prospective cohort studies reporting data on the association between UPF intake (defined by the NOVA classification) and the risk of incident diabetes or its complications in adults (>18 years). Meta-analysis was performed using random-effects modelling to obtain pooled hazard ratios (HRs) with 95 % confidence intervals (CIs), and the GRADE approach was applied to evaluate the certainty of evidence.

RESULTS

We included 14 prospective cohort studies with a total of 692,508 participants. The highest UPF consumption was significantly associated with an increased risk of diabetes (n = 9 studies; HR 1.24, 95 % CI 1.14 to 1.34, I2 = 69 %) compared with the lowest UPF intake (very low certainty of evidence). Subgroup analysis showed that studies published in 2024 had a smaller effect size compared with earlier studies. There were no significant differences between subgroups based on study location, duration of follow-up, method and frequency of dietary intake assessment, and risk of bias. Sensitivity analyses did not change these findings. Each 10 % increase in total UPF consumption was associated with a 13 % (n = 4 studies; HR 1.13, 95 % CI 1.08 to 1.18, I2 = 37 %) increased risk of diabetes. Preliminary data from 4 cohort studies also suggest that high UPF consumption may be associated with complications in diabetic patients, including microvascular/cardiovascular disease, chronic kidney disease, and mortality.

CONCLUSION

UPF consumption is associated with a higher risk of incident diabetes and may contribute to its complications. Urgent public health efforts should prioritize the reduction of UPF consumption.

Beneath the Surface: The Emerging Role of Ultra-Processed Foods in Obesity-Related Cancer

PURPOSEOF REVIEW

Ultra-processed foods (UPFs) are becoming more and more important in daily diets around the world; in some cases, they can account for as much as 60% of daily energy intake. Epidemiological evidence suggests that this shift toward high levels of food processing may be partially responsible for the global obesity epidemic and the rise in the prevalence of chronic diseases.

RECENT FINDINGS

Few prospective studies have examined the relationship between UPF consumption and cancer outcomes. According to currently available information, UPFs may increase the risk of cancer due to their obesogenic properties and exposure to substances that can cause cancer, such as certain food additives and pollution from product processing. The complex relationship between obesity and cancer involves factors such as immune dysregulation, altered adipokine and sex hormone levels, abnormal fatty acid metabolism, extracellular matrix remodeling, and chronic inflammation. Addressing cancer risk associated with UPF consumption could involve a multifaceted approach, including consumer behavior modification programs and robust public health regulations aimed at enhancing food environments. Improved knowledge of the potential dual negative impacts of UPFs on the environment and cancer risk is one of the priority areas we identify for future research and policy implications. Various approaches could be used to prevent cancers associated with UPF consumption, such as consumer behavior change programs and stricter public health regulations needed to improve the food environment. This review examines for the first time the potential role of UPFs in cancer risk associated with obesity, exploring underlying biological mechanisms and identifying key areas for future research and policy action, including the dual environmental and health impact of UPFs.

Ultra-processed foods and risk of declined renal function: a dose-response meta-analysis of 786,216 participants

OBJECTIVES

Earlier investigations have documented an association between elevated consumption of Ultra-Processed Foods (UPFs) and adverse renal outcomes. To explore this relationship further, we executed a comprehensive dose-response meta-analysis to examine the link between UPFs intake and the risk of declined renal function.

SETTING

A systematic search was completed utilizing the ISI Web of Science, Scopus, Embase as well as PubMed/MEDLINE databases (without any restrictions), up until September 5, 2024. Effect sizes of declined renal function were recalculated by applying a random effects model. The GRADE tool was adopted to assess the certainty of the evidence, while study quality and potential publication bias were examined via validated methods such as the Newcastle-Ottawa Scale, Egger's regression asymmetry and Begg's rank correlation test.

RESULTS

Thirty-three studies (comprising 786,216 participants) were incorporated in the quantitative analysis. The results demonstrated that a greater UPFs intake was significantly associated with an enhanced risk of declined renal function (RR = 1.16; 95% CI: 1.09, 1.23; I2 = 68.8%; p < 0.001; n = 37). Additionally, we observed that each 1-serving-per-day increase in UPFs consumption was associated to a 5% greater risk of reduced renal function (RR = 1.05; 95% CI: 1.02, 1.09; I2 = 80.9%; p = 0.013; n = 9). A positive, linear association between UPF intake and the risk of declined renal function (Pnonlinearity = 0.107, Pdose-response < 0.001) was further displayed in the non-linear dose-response analysis.

CONCLUSION

Greater exposure to UPFs is positively associated with the risk of declined renal function. The information emphasizes the importance of considering UPFs in the prevention and management of adverse renal outcomes.

Food supply toxicants and additives alter the gut microbiota and risk of metabolic disease

Metabolic disease is rising along with both global industrialization and the use of new commercial, agricultural, and industrial chemicals and food additives. Exposure to these compounds may contribute to aspects of metabolic diseases such as obesity, diabetes, and fatty liver disease. Ingesting compounds in the food supply is a key route of human exposure, resulting in the interaction between toxicants or additives and the intestinal microbiota. Toxicants can influence the composition and function of the gut microbiota, and these microbes can metabolize and transform toxicants and food additives. Microbe-toxicant interactions in the intestine can alter host mucosal barrier function, immunity, and metabolism, which may contribute to the risk or severity of metabolic disease development. Targeting the connection between toxicants, food, and immunity in the gut using strategies such as fermentable fiber (i.e., inulin) may mitigate some of the effects of these compounds on host metabolism. Understanding causative factors in the microbe-host relationship that promote toxicant-induced dysmetabolism is an important goal. This review highlights the role of common toxicants (i.e., persistent organic pollutants, pesticides, and fungicides) and food additives (emulsifiers and artificial sweeteners) found in our food supply that alter the gut microbiota and promote metabolic disease development.

Food additives and their impact on human health

Increasing evidence suggests that high consumption of ultra-processed foods (UPF) is associated with an increase in noncommunicable diseases, overweight, and obesity. This review aimed to verify the association of UPF with inflammatory diseases, especially allergic diseases. To identify relevant articles, an extensive literature search was conducted using the two most important search sites - PubMed and Google Scholar. Specific Medical Subject Headings (MeSHes) such as "food additives and health," "food additives and immune system," and "food additives and diseases" were used to conduct an advanced search. Emulsifiers have been, particularly, implicated in disrupting intestinal barrier function, modifying gut microbiota, and promoting inflammation, which may contribute to the development of food allergies and inflammatory diseases. While food additives serve various functions in the food industry, concerns regarding their impact on health, particularly in systemic autoimmune and metabolic conditions, have been raised. Common additives have been associated with allergic reactions, intolerances, and sensitivities.

Polysorbate 80 and carboxymethylcellulose: A different impact on epithelial integrity when interacting with the microbiome

The consumption of dietary emulsifiers, including polysorbate 80 (P80) and sodium carboxymethylcellulose (CMC), has raised safety concerns due to its interaction with the intestinal microbiome. This study demonstrated that increasing concentrations of P80 and CMC added to a dynamic four-stage gut microbiota model (BFBL gut simulator) altered the microbiome composition and impacted epithelial integrity in a dose-dependent manner. 16S rDNA amplicon-based metagenomics analysis revealed that these emulsifiers increased microbial groups with proinflammatory capacities while decreasing microbial taxa known to enhance barrier function. Increasing doses of P80 significantly decreased Bacteroides dorei and Akkermansia, taxa associated with anti-inflammatory potential, while increasing doses of CMC were linked to a higher abundance of Ruminococcus torques and Hungatella, which negatively impact barrier function. Both emulsifiers displayed a different impact on epithelial integrity when interacting with the microbiome. On one hand, supernatants from the BFBL simulator fed with P80 disrupted epithelial integrity to a lesser extent than the additive alone. On the other hand, both the microbiota and the supernatants from the BFBL simulator fed with CMC diminished the epithelial integrity, though the additive itself did not. These findings highlight the need to incorporate the gut microbiome in the risk assessment of these additives.

Molecular characteristics of glycolipids determine oil-water interfacial behavior and in vitro lipid digestion kinetics

An extensive amount of research has been conducted on a multitude of emulsifiers regarding their effect on o/w emulsion characteristics and lipolysis kinetics. However, there is an emerging need towards the understanding of biobased emulsifier characteristics. Therefore, this research studied the effect of 6 glycolipids on interfacial tension, emulsion microstructure throughout in vitro digestion, and lipolysis kinetics. Findings showed that molecular differences between glycolipids, such as the degree of acetylation, lactonization, and symmetry, substantially affected their behavior on the oil-water (o/w) interface, lowering the interfacial tensions to values ranging between 2 and 18 mN/m. Glycolipids with a higher amount of acetyl groups, lower tendency to self-assemble, and/or smaller molecular volume on the interface, decreased the interfacial tension substantially more. Therefore, acetylated lactonic sophorolipid decreased the interfacial tension most, while non-acetylated sophoroside showed the smallest effect on the interfacial tension. While all emulsions were stable and initially had similar droplet sizes, some were unstable throughout the simulated upper digestive tract, resulting in significantly different hydrolysis behaviors. Acetylated lactonic sophorolipid and non-acetylated glucolipid were more hydrophobic than the remaining 4 glycolipids, causing this gastric instability resulting in lower lipolysis extents by the end of the small intestinal phase. The acetylated sophoroside emulsion was unstable during the small intestinal phase, attributed to bile salt interactions. Therefore, this research concludes that molecular changes between glycolipids give rise to significantly different emulsion and digestion properties. These insights can be used in future work to optimize glycolipid structure and subsequent functional properties.

Intestinal permeability, food antigens and the microbiome: a multifaceted perspective

The gut barrier encompasses several interactive, physical, and functional components, such as the gut microbiota, the mucus layer, the epithelial layer and the gut mucosal immunity. All these contribute to homeostasis in a well-regulated manner. Nevertheless, this frail balance might be disrupted for instance by westernized dietary habits, infections, pollution or exposure to antibiotics, thus diminishing protective immunity and leading to the onset of chronic diseases. Several gaps of knowledge still exist as regards this multi-level interaction. In this review we aim to summarize current evidence linking food antigens, microbiota and gut permeability interference in diverse disease conditions such as celiac disease (CeD), non-celiac wheat sensitivity (NCWS), food allergies (FA), eosinophilic gastrointestinal disorder (EOGID) and irritable bowel syndrome (IBS). Specific food elimination diets are recommended for CeD, NCWS, FA and in some cases for EOGID. Undoubtfully, each of these conditions is very different and quite unique, albeit food antigens/compounds, intestinal permeability and specific microbiota signatures orchestrate immune response and decide clinical outcomes for all of them.

Ultraprocessed Food Intake and Risk of Systemic Lupus Erythematosus Among Women Observed in the Nurses' Health Study Cohorts

OBJECTIVE

We assessed ultraprocessed food (UPF) intake and systemic lupus erythematosus (SLE) incidence within the prospective Nurses' Health Study (NHS) cohorts.

METHODS

A total of 204,175 women were observed (NHS 1984-2016; NHSII 1991-2017). Semiquantitative food frequency questionnaires were completed every two to four years. UPF intake was determined as per the Nova classification. Nurses self-reported new doctor-diagnosed SLE, confirmed by medical records. Time-varying Cox regressions estimated hazard ratios (HRs; 95% confidence intervals [CIs]) for patients with incident SLE and SLE by anti-double-stranded DNA (dsDNA) antibody at diagnosis, according to cumulatively updated daily (a) UPF servings, (b) total intake (in grams and milliliters), and (c) percentage of total intake. Analyses adjusted for age, race, cohort, caloric and alcohol intakes, household income, smoking, body mass index (BMI), physical activity, menarchal age, and oral contraceptive use. We tested for interaction with BMI and examined UPF categories.

RESULTS

Mean baseline age was ~50 years (NHS) and ~36 years (NHSII); 93% self-reported White race. A total of 212 patients with incident SLE were identified. SLE risk was higher in the third versus first UPF tertile (servings per day pooled multivariable [MV] HR 1.56, 95% CI 1.04-2.32; P = 0.03). Results were stronger for dsDNA antibody in patients with SLE (servings per day pooled MV HR 2.05, 95% CI 1.15-3.65; P = 0.01) and for absolute (servings or total) than percentage of total intake. Sugar-sweetened/artificially sweetened beverages were associated with SLE risk (third vs first tertile MV HR 1.45, 95% CI 1.01-2.09). No BMI interactions were observed.

CONCLUSION

Higher cumulative average daily UPF intake was associated with >50% increased SLE risk and with doubled risk for anti-dsDNA antibody in patients with SLE. Many deleterious effects on systemic inflammation and immunity are postulated.

Food additives and their implication in inflammatory bowel disease and metabolic syndrome

Over the past half a century the Western diet (WD) has become saturated with food additives. During the same time, there has been an increase in Western diseases, such as inflammatory bowel disease (IBD) and metabolic syndrome (MetS). Emerging research has shown that food additives may be implicated in these diseases. However, critics have suggested that some of this research is problematic and may cause unnecessary fear amongst consumers. Here we review the emerging research concerning food additives and their implication in IBD and MetS, and criticisms thereof. To make the review more relevant to the WD, we only included common food additives, selected using supermarket data. Over a dozen common food additives from four categories were identified for their potential role in directly promoting these diseases. A consistent limitation of the research was the use of unrealistic human exposure conditions, such as high doses and modes of administration, as well as a lack of human trials. Another limitation was the absence of studies investigating the potential synergetic effect of consuming multiple food additives, as is common in the WD. Despite the limitations, there is some evidence that common food additives may be contributing to these additives, especially via their dysbiotic effect on the gut microbiota.

The complex link between the gut microbiome and obesity-associated metabolic disorders: Mechanisms and therapeutic opportunities

Microbial interactions are widespread and important processes that support the link between disease and microbial ecology. The gut microbiota is a major source of microbial stimuli that can have detrimental or beneficial effects on human health. It is also an endocrine organ that maintains energy homeostasis and host immunity. Obesity is a highly and increasingly prevalent metabolic disease and the leading cause of preventable death worldwide. An imbalance in the gut microbiome is associated with several diseases including obesity-related metabolic disorders. This review summarizes the complex association between the gut microbiome and obesity-associated metabolic diseases and validates the role and mechanisms of ecological dysregulation in the gut in obesity-associated metabolic disorders. Therapies that could potentially alleviate obesity-associated metabolic diseases by modulating the gut microbiota are discussed.

A Comprehensive Review of the Triangular Relationship among Diet-Gut Microbiota-Inflammation

The human gastrointestinal tract hosts a complex and dynamic community of microorganisms known as the gut microbiota, which play a pivotal role in numerous physiological processes, including digestion, metabolism, and immune function. Recent research has highlighted the significant impact of diet on the gut microbiota composition and functionality, and the consequential effects on host health. Concurrently, there is growing evidence linking the gut microbiota to inflammation, a key factor in many chronic diseases such as inflammatory bowel disease (IBD), obesity, diabetes, and cardiovascular diseases (CVDs). This review explores how dietary components influence the gut microbiota composition, how these microbial changes affect inflammatory pathways, and the therapeutic implications of modulating this axis for chronic inflammatory disease prevention and management. Beneficial dietary patterns, such as the Mediterranean diet (MD) and plant-based diets, promote a diverse and balanced gut microbiota composition, supporting anti-inflammatory pathways. Conversely, the Western diet (WD), high in saturated fats and refined sugars, is associated with dysbiosis and increased inflammation. With all the links between the three variables considered, this review attempts to offer a thorough examination of the triangle formed by inflammation, the gut microbiota, and food.

Food Additives' Impact on Gut Microbiota and Metabolic Syndrome: A Systematic Review

The human gut microbiota (GM) might play a significant role in the development or remission of metabolic syndrome (MetS) and associated disorders. Contributing factors include diets rich in unhealthy, processed foods that contain preservatives, emulsifiers, and stabilizers. Diet influences the GM's composition, diversity, and species richness in a time-dependent manner. Food additives can alter the GM and contribute to the pathophysiology of MetS by disrupting the intestinal barrier and inducing low-grade systemic inflammation. Our systematic review aims to clarify the relationships among food additives, GM, and MetS. We summarize current knowledge on how food additives interact with GM and the pathogenic role of the microbiota in the development of MetS, including obesity and type 2 diabetes. This review also discusses how disturbances in GM caused by stabilizers and emulsifiers may link to MetS, highlighting the impact of this condition on the development of diabetes and obesity. Furthermore, this review seeks a detailed explanation of how dietary choices related to GM dysbiosis may contribute to MetS. However, more comprehensive and well-designed in vitro, animal, and clinical studies are needed for a better understanding, as research on the role of GM in MetS is still emerging.

Unraveling the Evolutionary Diet Mismatch and Its Contribution to the Deterioration of Body Composition

Over the millennia, patterns of food consumption have changed; however, foods were always whole foods. Ultra-processed foods (UPFs) have been a very recent development and have become the primary food source for many people. The purpose of this review is to propose the hypothesis that, forsaking the evolutionary dietary environment, and its complex milieu of compounds resulting in an extensive metabolome, contributes to chronic disease in modern humans. This evolutionary metabolome may have contributed to the success of early hominins. This hypothesis is based on the following assumptions: (1) whole foods promote health, (2) essential nutrients cannot explain all the benefits of whole foods, (3) UPFs are much lower in phytonutrients and other compounds compared to whole foods, and (4) evolutionary diets contributed to a more diverse metabolome. Evidence will be presented to support this hypothesis. Nutrition is a matter of systems biology, and investigating the evolutionary metabolome, as compared to the metabolome of modern humans, will help elucidate the hidden connections between diet and health. The effect of the diet on the metabolome may also help shape future dietary guidelines, and help define healthy foods.

Carrageenan in the Diet: Friend or Foe for Inflammatory Bowel Disease?

While the exact pathogenesis of IBD remains unclear, genetic, environmental and nutritional factors as well as the composition of the gut microbiome play crucial roles. Food additives, which are increasingly consumed in the Western diet, are being investigated for their potential effects on IBD. These additives can affect gut health by altering the composition of the microbiota, immune responses, and intestinal permeability, contributing to autoimmune diseases and inflammation. Despite the growing number of studies on food additives and IBD, the specific effects of carrageenan have not yet been sufficiently researched. This review addresses this gap by critically analyzing recent studies on the effects of carrageenan on the gut microbiota, intestinal permeability, and inflammatory processes. We searched the MEDLINE and SCOPUS databases using the following terms: carrageenan, carrageenan and inflammatory bowel disease, carrageenan and cancer, food additives and microbiome, food additives and intestinal permeability, and food additives and autoimmune diseases. In animal studies, degraded carrageenan has been shown to trigger intestinal ulceration and inflammation, highlighting its potential risk for exacerbating IBD. It can affect the gut microbiota, reduce bacterial diversity, and increase intestinal permeability, contributing to "leaky gut" syndrome. Some studies suggest that carrageenan may inhibit the growth of cancer cells by influencing the progression of the cell cycle, but the anti-cancer effect is still unclear. Carrageenan may also increase glucose intolerance and insulin resistance. Further research is needed to determine whether carrageenan should be excluded from the diet of individuals with IBD.

Food additive emulsifiers and the risk of type 2 diabetes: analysis of data from the NutriNet-Santé prospective cohort study

BACKGROUND

Experimental studies have suggested potential detrimental effects of emulsifiers on gut microbiota, inflammation, and metabolic perturbations. We aimed to investigate the associations between exposures to food additive emulsifiers and the risk of type 2 diabetes in a large prospective cohort of French adults.

METHODS

We analysed data from 104 139 adults enrolled in the French NutriNet-Santé prospective cohort study from May 1, 2009, to April 26, 2023; 82 456 (79·2%) were female and the mean age was 42·7 years (SD 14·5). Dietary intakes were assessed with three 24 h dietary records collected over three non-consecutive days, every 6 months. Exposure to additive emulsifiers was evaluated through multiple food composition databases and ad-hoc laboratory assays. Associations between cumulative time-dependent exposures to food additive emulsifiers and the risk of type 2 diabetes were characterised with multivariable proportional hazards Cox models adjusted for known risk factors. The NutriNet-Santé study is registered at ClinicalTrials.gov (NCT03335644).

FINDINGS

Of 104 139 participants, 1056 were diagnosed with type 2 diabetes during follow-up (mean follow-up duration 6·8 years [SD 3·7]). Intakes of the following emulsifiers were associated with an increased risk of type 2 diabetes: total carrageenans (hazard ratio [HR] 1·03 [95% CI 1·01-1·05] per increment of 100 mg per day, p<0·0001), carrageenans gum (E407; HR 1·03 [1·01-1·05] per increment of 100 mg per day, p<0·0001), tripotassium phosphate (E340; HR 1·15 [1·02-1·31] per increment of 500 mg per day, p=0·023), acetyl tartaric acid esters of monoglycerides and diglycerides of fatty acids (E472e; HR 1·04 [1·00-1·08] per increment of 100 mg per day, p=0·042), sodium citrate (E331; HR 1·04 [1·01-1·07] per increment of 500 mg per day, p=0·0080), guar gum (E412; HR 1·11 [1·06-1·17] per increment of 500 mg per day, p<0·0001), gum arabic (E414; HR 1·03 [1·01-1·05] per increment of 1000 mg per day, p=0·013), and xanthan gum (E415, HR 1·08 [1·02-1·14] per increment of 500 mg per day, p=0·013).

INTERPRETATION

We found direct associations between the risk of type 2 diabetes and exposures to various food additive emulsifiers widely used in industrial foods, in a large prospective cohort of French adults. Further research is needed to prompt re-evaluation of regulations governing the use of additive emulsifiers in the food industry for better consumer protection.

FUNDING

European Research Council, French National Cancer Institute, French Ministry of Health, IdEx Université de Paris, and Bettencourt-Schueller Foundation.

Ultra-Processed Foods-Dietary Foe or Potential Ally?

The prevalence of non-communicable diseases (NCDs) has steadily increased in the United States. Health experts attribute the increasing prevalence of NCDs, in part, to the consumption of ultra-processed foods (UPFs) based on epidemiological observations. However, no definitive evidence of causality has been established. Consequently, there is an ongoing debate over whether adverse health outcomes may be due to the low nutrient density per kilocalorie, the processing techniques used during the production of UPFs, taste preference-driven overconsumption of calories, or unidentified factors. Recognizing that "the science is not settled," we propose an investigative process in this narrative review to move the field beyond current controversies and potentially identify the basis of causality. Since many consumers depend on UPFs due to their shelf stability, affordability, availability, ease of use, and safety from pathogens, we also suggest a paradigm for guiding both the formulation of UPFs by food designers and the selection of UPFs by consumers.

The distribution, fate, and environmental impacts of food additive nanomaterials in soil and aquatic ecosystems

Nanomaterials in the food industry are used as food additives, and the main function of these food additives is to improve food qualities including texture, flavor, color, consistency, preservation, and nutrient bioavailability. This review aims to provide an overview of the distribution, fate, and environmental and health impacts of food additive nanomaterials in soil and aquatic ecosystems. Some of the major nanomaterials in food additives include titanium dioxide, silver, gold, silicon dioxide, iron oxide, and zinc oxide. Ingestion of food products containing food additive nanomaterials via dietary intake is considered to be one of the major pathways of human exposure to nanomaterials. Food additive nanomaterials reach the terrestrial and aquatic environments directly through the disposal of food wastes in landfills and the application of food waste-derived soil amendments. A significant amount of ingested food additive nanomaterials (> 90 %) is excreted, and these nanomaterials are not efficiently removed in the wastewater system, thereby reaching the environment indirectly through the disposal of recycled water and sewage sludge in agricultural land. Food additive nanomaterials undergo various transformation and reaction processes, such as adsorption, aggregation-sedimentation, desorption, degradation, dissolution, and bio-mediated reactions in the environment. These processes significantly impact the transport and bioavailability of nanomaterials as well as their behaviour and fate in the environment. These nanomaterials are toxic to soil and aquatic organisms, and reach the food chain through plant uptake and animal transfer. The environmental and health risks of food additive nanomaterials can be overcome by eliminating their emission through recycled water and sewage sludge.

Predispose, precipitate, perpetuate, and protect: how diet and the gut influence mental health in emerging adulthood

Medicine often employs the 4Ps of predisposing, precipitating, perpetuating, and protective factors to identify salient influences on illness states, and to help guide patient care. Mental illness is a significant cause of morbidity and mortality worldwide. Mental health is a complex combination of biological, psychological, environmental, and social factors. There is growing interest in the gut-brain-microbiome (GBM) axis and its impact on mental health. We use the medical model of the 4Ps to explore factors involving the connection between nutrition and the GBM axis and their associated risks with mental health problems in emerging adults (EAs), a life stage when mental illness onset is the most common. We review the impact of current dietary trends on the GBM and on mental health, and the role that gut microbiome-based interventions can have in modulating the GBM axis of EAs. We discuss the implications of gut health on the GBM and areas for clinical intervention.

The Prebiotic Diet: Other Dietary Molecules Implicated in Gut Microbiota Health

In 2016, the International Scientific Association for Probiotics and Prebiotics (ISAPP) provided a new definition of a prebiotic as "a substrate that is selectively utilized by host microorganisms conferring a health benefit" [...].

Evidence and hypotheses on adverse effects of the food additives carrageenan (E 407)/processed Eucheuma seaweed (E 407a) and carboxymethylcellulose (E 466) on the intestines: a scoping review

This scoping review provides an overview of publications reporting adverse effects on the intestines of the food additives carrageenan (CGN) (E 407)/processed Eucheuma seaweed (PES) (E 407a) and carboxymethylcellulose (CMC) (E 466). It includes evidence from human, experimental mammal and in vitro research publications, and other evidence. The databases Medline, Embase, Scopus, Web of Science Core Collection, Cochrane Database of Systematic Reviews and Epistemonikos were searched without time limits, in addition to grey literature. The publications retrieved were screened against predefined criteria. From two literature searches, 2572 records were screened, of which 224 records were included, as well as 38 records from grey literature, making a total of 262 included publications, 196 on CGN and 101 on CMC. These publications were coded and analyzed in Eppi-Reviewer and data gaps presented in interactive maps. For CGN, five, 69 and 33 research publications on humans, experimental mammals and in vitro experiments were found, further separated as degraded or native (non-degraded) CGN. For CMC, three human, 20 animal and 14 in vitro research publications were obtained. The most studied adverse effects on the intestines were for both additives inflammation, the gut microbiome, including fermentation, intestinal permeability, and cancer and metabolic effects, and immune effects for CGN. Further studies should focus on native CGN, in the form and molecular weight used as food additive. For both additives, randomized controlled trials of sufficient power and with realistic dietary exposure levels of single additives, performed in persons of all ages, including potentially vulnerable groups, are needed.

Flavour, emulsifiers and colour are the most frequent markers to detect food ultra-processing in a UK food market analysis

OBJECTIVE

To elucidate which markers of ultra-processing (MUP) and their combinations are best suited to detect ultra-processed food (UPF).

DESIGN

The study was based on the 206 food and 32 beverage items of the Oxford WebQ which encompass all major foods consumed in the UK. For each Oxford WebQ question, ingredient lists of up to ten matching different commercial products (n 2146) were researched online using data from the two market leaders of groceries in the UK sorted by relevance (Tesco) and by top sellers (Sainsbury's), respectively. According to the NOVA classification, sixty-five MUP were defined, and if the ingredient list of a food product was positive for at least one MUP, it was regarded as UPF. The percentage of UPF items containing specific MUP was calculated. In addition, all combinations of two to six different MUP were assessed concerning the percentage of identified UPF items.

SETTING

Cross-sectional analysis.

PARTICIPANTS

None.

RESULTS

A total of 990 products contained at least one MUP and were, therefore, regarded as UPF. The most frequent MUP were flavour (578 items, 58·4 % of all UPF), emulsifiers (353 items, 35·7 % of all UPF) and colour (262 items, 26·5 % of all UPF). Combined, these three MUP detected 79·2 % of all UPF products. Detection rate increased to 88·4 % of all UPF if ingredient lists were analysed concerning three additional MUP, that is, fibre, dextrose and firming agent.

CONCLUSIONS

Almost 90 % of all UPF items can be detected by six MUP.

Alterations in intestinal Archaea composition in pediatric patients with Crohn's disease based on next-generation sequencing - a pilot study

Intestinal dysbiosis can lead to the induction of systemic immune-mediated inflammatory diseases, such as Crohn's disease Although archaea are part of the commensal microbiota, they are still one of the least studied microorganisms. The aim of our study was the standardization of the optimal conditions and primers for sequencing of the gut archaeome using Next Generation Sequencing, and evaluation of the differences between the composition of archaea in patients and healthy volunteers, as well as analysis of the changes that occur in the archaeome of patients depending on disease activity. Newly diagnosed patients were characterized by similar archeal profiles at every taxonomic level as in healthy individuals (the dominance of Methanobacteria at the class level, and Methanobrevibacter at the genus level). In turn, in patients previously diagnosed with Crohn's disease (both in active and remission phase), an increased prevalence of Thermoplasmata, Thermoprotei, Halobacteria (at the class level), and Halococcus, Methanospaera or Picrophilus (at the genus level) were observed. Furthermore, we have found a significant correlation between the patient's parameters and the individual class or species of Archaea. Our study confirms changes in archaeal composition in pediatric patients with Crohn's disease, however, only in long-standing disease. At the beginning of the disease, the archeal profile is similar to that of healthy people. However, in the chronic form of the disease, significant differences in the composition of archaeome begin to appear. It seems that some archaea may be a good indicator of the chronicity and activity of Crohn's disease.

Emulsifiers in ultra-processed foods in the UK food supply

OBJECTIVE

Ultra-processed foods (UPF), including those containing food additive emulsifiers, have received research attention due to evidence implicating them in the pathogenesis of certain diseases. The aims of this research were to develop a large-scale, brand-level database of UPF in the UK food supply and to characterise the occurrence and co-occurrence of food additive emulsifiers.

DESIGN

A database was compiled sampling all products from the food categories contributing to energy intake from UPF in the UK from the National Diet and Nutrition Survey (2008-2014). Every food in these categories were identified from online supermarket provision from the 'big four' supermarkets that dominate the market share in the UK, comprising Tesco, Sainsbury's, Asda and Morrisons.

SETTING

Major supermarkets in the UK.

RESULTS

A total of 32 719 food products in the UK supermarket food supply were returned in searches. Of these, 12 844 products were eligible and manually reviewed for the presence of emulsifiers. Emulsifiers were present in 6642 (51·7 %) food products. Emulsifiers were contained in 95·0 % of 'Pastries, buns and cakes', 81·9 % of 'Milk-based drinks', 81·0 % of 'Industrial desserts' and 77·5 % of 'Confectionary'. Fifty-one per cent of all emulsifier-containing foods contained multiple emulsifiers. Across emulsifier-containing foods, there were a median of two emulsifiers (IQR 2) per product. The five most common emulsifiers were lecithin (23·4 % of all products), mono- and diglycerides of fatty acids (14·5 %), diphosphates (11·6 %), and xanthan gum and pectin (8·0 %).

CONCLUSIONS

Findings from this study are the first to demonstrate the widespread occurrence and co-occurrence of emulsifiers in UPF in the UK food supply.

Low Emulsifier Diet in Healthy Female Adults: A Feasibility Study of Nutrition Education and Counseling Intervention

Emulsifiers are food additives commonly found in processed foods to improve texture stabilization and food preservation. Dietary emulsifier intake can potentially damage the gut mucosal lining resulting in chronic inflammation such as Crohn's disease. This study investigates the feasibility of a low-emulsifier diet among healthy female adults, as no previous reports have studied the feasibility of such a diet on healthy participants. A quasi-experimental study for a nutrition education and counseling intervention was conducted over 14 days among healthy Saudi participants aged 18 years and over. Assessment of dietary intake using 3-day food records was conducted at the baseline and 2-week follow-up. Participants attended an online educational session using the Zoom application illustrating instructions for a low-emulsifier diet. Daily exposure to emulsifiers was evaluated and nutrient intake was measured. A total of 30 participants completed the study. At baseline, 38 emulsifiers were identified, with a mean ± SD exposure of 12.23 ± 10.07 emulsifiers consumed per day. A significant reduction in the mean frequency of dietary emulsifier intake was observed at the end of the intervention (12.23 ± 10.07 vs. 6.30 ± 7.59, p < 0.01). However, intake of macronutrients and micronutrients was significantly reduced (p < 0.05). Good adherence to the diet was achieved by 40% of the participants, and 16.66% attained a 50% reduction of emulsifier intake. The study demonstrates that a low-emulsifier diet provided via dietary advice is feasible to follow and tolerable by healthy participants. However, the diet still needs further investigation and assessment of it is nutritional intake and quality before implementing it in patients with inflammatory bowel disease who are at high risk of poor nutritional intake.

Ultraprocessed Foods and Obesity Risk: A Critical Review of Reported Mechanisms

Epidemiologic evidence supports a positive association between ultraprocessed food (UPF) consumption and body mass index. This has led to recommendations to avoid UPFs despite very limited evidence establishing causality. Many mechanisms have been proposed, and this review critically aimed to evaluate selected possibilities for specificity, clarity, and consistency related to food choice (i.e., low cost, shelf-life, food packaging, hyperpalatability, and stimulation of hunger/suppression of fullness); food composition (i.e., macronutrients, food texture, added sugar, fat and salt, energy density, low-calorie sweeteners, and additives); and digestive processes (i.e., oral processing/eating rate, gastric emptying time, gastrointestinal transit time, and microbiome). For some purported mechanisms (e.g., fiber content, texture, gastric emptying, and intestinal transit time), data directly contrasting the effects of UPF and non-UPF intake on the indices of appetite, food intake, and adiposity are available and do not support a unique contribution of UPFs. In other instances, data are not available (e.g., microbiome and food additives) or are insufficient (e.g., packaging, food cost, shelf-life, macronutrient intake, and appetite stimulation) to judge the benefits versus the risks of UPF avoidance. There are yet other evoked mechanisms in which the preponderance of evidence indicates ingredients in UPFs actually moderate body weight (e.g., low-calorie sweetener use for weight management; beverage consumption as it dilutes energy density; and higher fat content because it reduces glycemic responses). Because avoidance of UPFs holds potential adverse effects (e.g., reduced diet quality, increased risk of food poisoning, and food wastage), it is imprudent to make recommendations regarding their role in diets before causality and plausible mechanisms have been verified.

Impact of Diet on Gut Microbiota Composition and Microbiota-Associated Functions in Heart Failure: A Systematic Review of In Vivo Animal Studies

Heart failure (HF) represents a cardiovascular disease with high mortality and morbidity. The latest evidence shows that changes in the composition of the gut microbiota might play a pivotal role in the prevention and management of HF. This systematic review aims at assessing the potential associations between the diet, gut microbiota, and derived metabolites with the outcomes of HF. A systematic literature search was performed up to July 2022 on the PubMed, Web of Science, and Scopus databases. The PRISMA guidelines were followed when possible. The risk of bias was assessed with the SYRCLE and ARRIVE tools. A total of nine pre-clinical studies on animal models, with considerable heterogeneity in dietary interventions, were included. High-fiber/prebiotic diets (n = 4) and a diet rich in polyphenols (n = 1) modified the gut microbiota composition and increased microbial metabolites' activities, linked with an improvement in HF outcomes, such as a reduction in systolic blood pressure, cardiac hypertrophy, and left ventricular thickness. A high-fat diet (n = 2) or a diet rich in choline (n = 2) induced an increase in TMAO and indole derivative production associated with a decrease in cardiac function, systemic endotoxemia, and inflammation and an increase in cardiac fibrosis and cardiac remodeling. Although results are retrieved from animal studies, this systematic review shows the key role of the diet-especially a high-fiber and prebiotic diet-on gut microbial metabolites in improving HF outcomes. Further studies on human cohorts are needed to identify personalized therapeutic dietary interventions to improve cardiometabolic health.

Dietary Emulsifiers Exacerbate Food Allergy and Colonic Type 2 Immune Response through Microbiota Modulation

The significant increase in food allergy incidence is correlated with dietary changes in modernized countries. Here, we investigated the impact of dietary emulsifiers on food allergy by employing an experimental murine model. Mice were exposed to drinking water containing 1.0% carboxymethylcellulose (CMC) or Polysorbate-80 (P80) for 12 weeks, a treatment that was previously demonstrated to induce significant alterations in microbiota composition and function leading to chronic intestinal inflammation and metabolic abnormalities. Subsequently, the ovalbumin food allergy model was applied and characterized. As a result, we observed that dietary emulsifiers, especially P80, significantly exacerbated food allergy symptoms, with increased OVA-specific IgE induction and accelerated type 2 cytokine expressions, such as IL-4, IL-5, and IL-13, in the colon. Administration of an antibiotic regimen completely reversed the emulsifier-induced exacerbated susceptibility to food allergy, suggesting a critical role played by the intestinal microbiota in food allergy and type 2 immune responses.