Plant-Based Meat Analogues Weaken Gastrointestinal Digestive Function and Show Less Digestibility Than Real Meat in Mice

Causal relationship between cheese intake and risk of gastroesophageal reflux disease and Barrett's esophagus: findings from multivariable mendelian randomization and mediation analysis

OBJECTIVE

Previous studies have indicated a potential correlation between cheese intake and risk of various diseases. However, establishing a causal relationship is challenging. To address this, we employed Mendelian randomization (MR) to simulate randomized trial groups and to investigate whether there is a causal link between cheese intake and the risk of gastroesophageal reflux disease (GERD) and Barrett's esophagus.

METHODS

We conducted a multivariable MR analysis using individual-level data on GERD and Barrett's esophagus from the published datasets. Univariable and multivariable MR investigations were carried out to explore and substantiate the causal association between genetically predicted cheese intake and esophageal diseases. Additionally, a network MR analysis was executed to identify potential intermediate variables.

RESULTS

Based on the primary causal effects model using MR analyses with the inverse-variance weighted (IVW) method, the genetically predicted that cheese intake demonstrated a protective factor of GERD (OR = 0.356; 95% CI 0.256-0.495; P = 8.22E-10) and Barrett's esophagus (OR = 0.223; 95% CI 0.114-0.437; P = 1.19E-5). These effects remained consistent after adjusting for potential confounders such as tobacco smoking (GERD: OR = 0.440; 95% CI 0.347 - 0.558; P = 1.17E-11; Barrett's esophagus: OR = 0.263; 95% CI 0.160 - 0.432; P = 1.33E-7) and BMI (GERD: OR = 0.515; 95% CI 0.424 - 0.626; P = 2.49E-11; Barrett's esophagus: OR = 0.402; 95% CI 0.243 - 0.664; P = 3.72E-4). Furthermore, the network MR showed that BMI mediated 28.10% and 27.50% of the causal effect of cheese intake on GERD and Barrett's esophagus, respectively, with statistically significant mediation effects.

CONCLUSION

The multivariable MR analysis conducted in this study revealed a reverse causal relationship between cheese intake and GERD and Barrett's esophagus. Furthermore, BMI was potential mediating factor of the cheese intake effects on GERD and Barrett's esophagus. This finding provides causal evidence for the potential protective role of cheese intake in the prevention of esophageal diseases. The mediating effect of BMI suggests that dietary interventions combined with weight management may help reduce the risk of these diseases.

Gastrointestinal fate of proteins from commercial plant-based meat analogs: Silent passage through the stomach, oxidative stress in intestine, and gut dysbiosis in Wistar rats

Plant-based meat analogs (PBMAs) are common ultra-processed foods (UPFs) included in the vegan/vegetarian diets as presumed healthy alternatives to meat and meat products. However, such health claims need to be supported by scientific evidence. To gain further insight into this topic, two commercial UPFs typically sold as meat analogs, namely, seitan (S) and tofu (T), were included in a cereal-based chow and provided to Wistar rats for 10 weeks. A group of animals had, simultaneously, an isocaloric and isoprotein experimental diet formulated with cooked beef (B). In all cases, experimental chows (∼4 kcal/g feed) had their basal protein concentration increased from 14% to 30% using proteins from S, T, or B. Upon slaughter, in vivo protein digestibility was assessed, and the entire gastrointestinal tract (digests and tissues) was analyzed for markers of oxidative stress and untargeted metabolomics. Metagenomics was also applied to assess the variation of microbiota composition as affected by dietary protein. Diets based on PBMAs showed lower protein digestibility than those containing meat and promoted an intense luminal glycoxidative stress and an inflammatory intestinal response. The fermentation of undigested oxidized proteins from T in the colon of Wistar rats likely led to formation of mutagenic metabolites such as p-cresol. The presence of these compounds in the animal models raises concerns about the potential effects of full replacement of meat by certain PBMAs in the diet. Therefore, future research might target on translational human studies to shed light on these findings.

Ultra-processed vegan foods: Healthy alternatives to animal-source foods or avoidable junk?

Animal-source foods (ASFs), namely, meat, milk, eggs, and derived products, are crucial components of a well-balanced diet owing to their contribution with multiple essential nutrients. The benefits of the consumption of ASFs in terms of hedonic responses, emotional well-being, and mood are also widely documented. However, an increasing share of consumers decide to exclude ASFs from their diets. Some of these vegan consumers are inclined to consume so-called "meat" and/or "dairy analogs," which are produced from plant materials (soy, wheat, and oat, among others). In order to simulate appearance, texture, and flavor of ASFs, these industrial vegan foods are designed using an intricate formulation and industrial processing, which justifies their identification as ultraprocessed foods (UPFs). While the introduction of these processed vegan products is becoming popular in developed countries, the consequences of the sustained intake of these products on human health are mostly ignored. Contrarily to common belief, which emphasizes their role as "healthy" alternatives to ASFs, these plant-based UPFs may enclose certain threats, which are reviewed in the present paper. The remarkable differences between vegan UPFs and the genuine ASFs (meat/dairy products) from sensory, nutritional, hedonic, or health perspectives precludes the designation of the former as analogs of the latter. Understanding the basis of these differences would contribute to (i) providing consumers with grounds to make reasoned decisions to consume meat/dairy products and/or the vegan alternatives and (ii) providing food companies with strategies to produce more appealing, nutritive, and healthy industrially processed vegan products.

Untargeted metabolomics unravels distinct gut microbial metabolites derived from plant-based and animal-origin proteins using in vitro modeling

The popularity of plant-based meat alternatives (PBMAs) has sparked a contentious debate about their influence on intestinal homeostasis compared to traditional animal-based meats. This study aims to explore the changes in gut microbial metabolites (GMMs) induced by the gut microbiota on different digested patties: beef meat and pea-protein PBMA. After digesting in vitro, untargeted metabolomics revealed 32 annotated metabolites, such as carnitine and acylcarnitines correlated with beef meat, and 45 annotated metabolites, like triterpenoids and lignans, linked to our PBMA. Secondly, (un)targeted approaches highlighted differences in GMM patterns during colonic fermentations. Our findings underscore significant differences in amino acids and their derivatives. Beef protein fermentation resulted in higher production of methyl-histidine, gamma-glutamyl amino acids, indoles, isobutyric and isovaleric acids. In contrast, PBMAs exhibit a significant release of N-acyl amino acids and unique dipeptides, like phenylalanine-arginine. This research offers valuable insights into how PBMAs and animal-based proteins differently modulate intestinal microenvironments.

Smart proteins as a new paradigm for meeting dietary protein sufficiency of India: a critical review on the safety and sustainability of different protein sources

India, a global leader in agriculture, faces sustainability challenges in feeding its population. Although primarily a vegetarian population, the consumption of animal derived proteins has tremendously increased in recent years. Excessive dependency on animal proteins is not environmentally sustainable, necessitating the identification of alternative smart proteins. Smart proteins are environmentally benign and mimic the properties of animal proteins (dairy, egg and meat) and are derived from plant proteins, microbial fermentation, insects and cell culture meat (CCM) processes. This review critically evaluates the technological, safety, and sustainability challenges involved in production of smart proteins and their consumer acceptance from Indian context. Under current circumstances, plant-based proteins are most favorable; however, limited land availability and impending climate change makes them unsustainable in the long run. CCM is unaffordable with high input costs limiting its commercialization in near future. Microbial-derived proteins could be the most sustainable option for future owing to higher productivity and ability to grow on low-cost substrates. A circular economy approach integrating agri-horti waste valorization and C1 substrate synthesis with microbial biomass production offer economic viability. Considering the use of novel additives and processing techniques, evaluation of safety, allergenicity, and bioavailability of smart protein products is necessary before large-scale adoption.

Comparison of nutritional profile between plant-based meat analogues and real meat: A review focusing on ingredients, nutrient contents, bioavailability, and health impacts

In order to fully understand the nutritional heterogeneity of plant-based meat analogues and real meat, this review summarized their similarities and differences in terms of ingredients, nutrient contents, bioavailability and health impacts. Plant-based meat analogues have some similarities to real meat. However, plant-based meat analogues are lower in protein, cholesterol and VB12 but higher in dietary fiber, carbohydrates, sugar, salt and various food additives than real meat. Moreover, some nutrients in plant-based meat analogues, such as protein and iron, are less bioavailable. There is insufficient evidence that plant-based meat analogues are healthier, which may be related to the specific attributes of these products such as formulation and degree of processing. As things stand, it is necessary to provide comprehensive nutrition information on plant-based meat products so that consumers can make informed choices based on their nutritional needs.

Protein transition: focus on protein quality in sustainable alternative sources

The current consumption trends, combined with the expected demographic growth in the coming years, call for a protein transition, i.e., the partial substitution of animal protein-rich foods with foods rich in proteins produced in a more sustainable way. Here, we have discussed some of the most common and promising protein sources alternative to animal proteins, namely: legumes, insects, and microorganisms (including microalgae and fungi). The primary objective was to assess their nutritional quality through the collection of digestible indispensable amino acid score (DIAAS) values available in the scientific literature. Protein digestibility corrected amino acid score (PDCAAS) values have been used where DIAAS values were not available. The ecological impact of each protein source, its nutritional quality and the potential applications in traditional foods or novel food concepts like meat analogues are also discussed. The data collected show that DIAAS values for animal proteins are higher than all the other protein sources. Soybean proteins, mycoproteins and proteins of some insects present relatively high DIAAS (or PDCAAS) values and must be considered proteins of good quality. This review also highlights the lack of DIAAS values for many potentially promising protein sources and the variability induced by the way the proteins are processed.

Next-Generation Plant-Based Foods: Challenges and Opportunities

Owing to environmental, ethical, health, and safety concerns, there has been considerable interest in replacing traditional animal-sourced foods like meat, seafood, egg, and dairy products with next-generation plant-based analogs that accurately mimic their properties. Numerous plant-based foods have already been successfully introduced to the market, but there are still several challenges that must be overcome before they are adopted by more consumers. In this article, we review the current status of the science behind the development of next-generation plant-based foods and highlight areas where further research is needed to improve their quality, increase their variety, and reduce their cost, including improving ingredient performance, developing innovative processing methods, establishing structure-function relationships, and improving nutritional profiles.

Lacticaseibacillus Casei IDCC 3451 Strengthen Digestibility of Plant-based Proteins in Mice

The demand for plant-based proteins as alternative meat sources continues to increase because of environmental concerns, animal welfare, and religious reasons. However, plant-based proteins have low digestibility than real meat, which should be overcome. In the present study, the effect of co-administration of legumin protein mixture and the probiotic strain on plasma concentration of amino acids was investigated as a strategy of enhancement in protein digestion. First, the proteolytic activity of the four probiotic strains was compared. As a result, Lacticaseibacillus casei IDCC 3451 was identified as an optimal probiotic strain that efficiently digested the legumin protein mixture by forming the largest halo produced by proteolysis. Next, to investigate whether the co-administration of legumin protein mixture and L. casei IDCC 3451 could synergically improve digestibility, mice were fed either a high-protein diet or a high-protein diet with L. casei IDCC 3451 for 8 weeks. Compared to only in the high-protein diet only group, the concentrations of branched chain amino acids and essential amino acids were 1.36 and 1.41 times higher in the co-administered group, respectively. Therefore, co-supplementation of plant-based proteins with L. casei IDCC 3451 can be suggested to improve protein digestibility based on the this study.

Anionic polysaccharides benefit the bioavailability of pork myofibrillar protein gels: Evidence from a perspective of protein absorption and metabolism

This study aimed to probe the bioavailability of myofibrillar protein (MP) gels in mice as affected by incorporating anionic xanthan (XMP) and sodium alginate (SMP)/cationic chitosan (CSMP)/neutral curdlan (CMP) and konjac (KMP), respectively. The results showed that the numbers of peptides absorbed were obviously higher in anionic XMP and SMP groups (88 and 126, respectively) than in the cationic CSMP (51) group. The contents of free amino acids absorbed in SMP and XMP were significantly greater than that in CSMP and CMP groups (P < 0.05). Furthermore, the antioxidant capacity of bioactive compounds absorbed in the SMP group was higher than those in the other groups (P < 0.05), and the expression of tight junction protein (Occludin and ZO-1) was up-regulated in SMP group. The low contents of free ammonia, indole and p-cresol were observed in the anionic XMP, SMP and neutral KMP groups, compared to CSMP group. This work highlights the benefits of anionic polysaccharides (sodium alginate and xanthan) in developing low-fat meat products with high MP bioavailability.

Current Challenges and Future Directions in Peptidomics

The field of peptidomics has been under development since its start more than 20 years ago. In this chapter we provide a personal outlook for future directions in this field. The applications of peptidomics technologies are spreading more and more from classical research of peptide hormones and neuropeptides towards commercial applications in plant and food-science. Many clinical applications have been developed to analyze the complexity of biofluids, which are being addressed with new instrumentation, automization, and data processing. Additionally, the newly developed field of immunopeptidomics is showing promise for cancer therapies. In conclusion, peptidomics will continue delivering important information in classical fields like neuropeptides and peptide hormones, benefiting from improvements in state-of-the-art technologies. Moreover, new directions of research such as immunopeptidomics will further complement classical omics technologies and may become routine clinical procedures. Taken together, discoveries of new substances, networks, and applications of peptides can be expected in different disciplines.

Plant-based meat analogues enhance the gastrointestinal motility function and appetite of mice by specific volatile compounds and peptides

Eating behavior is critical for maintaining energy homeostasis. Previous studies have found that plant-based meat analogues increased diet intake in mice compared with animal meat under a free feeding mode, however the reasons were unclear. To explore the underlying mechanisms of plant-based meat analogues increasing diet intake, mice were fed animal or plant-based pork and beef analogue diets, respectively. Biochemical and histological analyses were performed to evaluate appetite-regulating hormones and gastrointestinal motility function. Peptiomics and GC-IMS were applied to identify key substances. We found that the intake of plant-based meat analogues significantly enhanced the gastrointestinal motility function of mice. The long-term intake (68 days) of plant-based meat analogues significantly increased the muscle layer thickness of the duodenum and jejunum of mice; the activity of gastrointestinal cells of Cajal were also promoted by upregulating the expression of c-kit related signals as compared to animal meat; plant-based meat analogues intake markedly enhanced the signal intensity of the intestinal neurotransmitter 5-hydroxytryptamine (5-HT) by upregulating the expression of 5-HT synthase and receptors but downregulating its transporter and catabolic enzyme in the intestine. Moreover, plant-based meat analogues intake significantly increased levels of appetite-stimulating factors in the peripheral or hypothalamus but reduced levels of appetite-suppressing factors compared with animal meat. Specific volatile compounds were significantly associated with appetite regulating factors. Among them, 7 substances such as linalool have a potential promoting effect on food intake. Besides, different digestive peptides in gastrointestinal tract may affect eating behavior mainly through the neuroactive ligand-receptor interaction pathway, exerting hormone-like effects or influencing endocrine cell secretion. These findings preliminarily clarified the mechanism of plant-based meat analogues promoting diet intake and provided a theoretical basis for a reasonable diet.

Effects of different processing degrees of plant-based meat on the blood biochemical level, inflammation and intestinal microorganisms in mice

In recent years, with the increasing health needs of people, plant-based meat products have gradually entered the public's vision. However, many plant-based meats on the market today are so heavily processed and use so many additives that they can be classified as ultra-processed foods (UPFs). Very limited studies report whether the benefits of these plant-based meats are discounted when lots of additives were added. In this experiment, mice were fed with processed plant-based meat, ultra-processed plant-based meat, low-processed red meat, ultra-processed red meat to compare the health effects. In this experiment, some serum biochemical indexes, hematoxylin-eosin (HE) staining of liver and intestine, 16s rDNA and short-chain fatty acids of mouse feces were detected. Compared with the negative control group, it was found that mice in the ultra-processed plant-based meat group, ultra-processed red meat group, and low-processed red meat group gained significant weight, and there exist intestinal inflammation and liver inflammation. In terms of gut microbiota, the diversity and structure of gut microbiota in both two plant-meat group was better than that in both two red-meat group. It can be concluded that plant-based meat and red meat cause different gut microbiota outcomes, which in turn affect body weight and the occurrence of liver and intestinal inflammation. What's more, plant-based meat is healthier than red meat, but overprocessing reduces the benefits of plant-based meat. There is a need to improve the way plant-based meat is processed and reduce the amount of additives used.

Ultraprocessed plant-based foods: Designing the next generation of healthy and sustainable alternatives to animal-based foods

Numerous examples of next-generation plant-based foods, such as meat, seafood, egg, and dairy analogs, are commercially available. These products are usually designed to have physicochemical properties, sensory attributes, and functional behaviors that match those of the animal-sourced products they are designed to replace. However, there has been concern about the potential negative impacts of these foods on human nutrition and health. In particular, many of these products have been criticized for being ultraprocessed foods that contain numerous ingredients and are manufactured using harsh processing operations. In this article, the concept of ultraprocessed foods is introduced and its relevance to describe the properties of next-generation plant-based foods is discussed. Most commercial plant-based meat, seafood, egg, and dairy analogs currently available do fall into this category, and so can be classified as ultraprocessed plant-based (UPB) foods. The nutrient content, digestibility, bioavailability, and gut microbiome effects of UPB foods are compared to those of animal-based foods, and the potential consequences of any differences on human health are discussed. Some commercial UPB foods would not be considered healthy based on their nutrient profiles, especially those plant-based cheeses that contain low levels of protein and high levels of fat, starch, and salt. However, it is argued that UPB foods can be designed to have good nutritional profiles and beneficial health effects. Finally, areas where further research are still needed to create a more healthy and sustainable food supply are discussed.

Significance of Fermentation in Plant-Based Meat Analogs: A Critical Review of Nutrition, and Safety-Related Aspects

Plant-based meat analogs have been shown to cause less harm for both human health and the environment compared to real meat, especially processed meat. However, the intense pressure to enhance the sensory qualities of plant-based meat alternatives has caused their nutritional and safety aspects to be overlooked. This paper reviews our current understanding of the nutrition and safety behind plant-based meat alternatives, proposing fermentation as a potential way of overcoming limitations in these aspects. Plant protein blends, fortification, and preservatives have been the main methods for enhancing the nutritional content and stability of plant-based meat alternatives, but concerns that include safety, nutrient deficiencies, low digestibility, high allergenicity, and high costs have been raised in their use. Fermentation with microorganisms such as Bacillus subtilis, Lactiplantibacillus plantarum, Neurospora intermedia, and Rhizopus oryzae improves digestibility and reduces allergenicity and antinutritive factors more effectively. At the same time, microbial metabolites can boost the final product's safety, nutrition, and sensory quality, although some concerns regarding their toxicity remain. Designing a single starter culture or microbial consortium for plant-based meat alternatives can be a novel solution for advancing the health benefits of the final product while still fulfilling the demands of an expanding and sustainable economy.

Novel plant-based meat alternatives: Implications and opportunities for consumer nutrition and health

Against the backdrop of the global protein transition needed to remain within planetary boundaries, there is an influx of plant-based meat alternatives that seek to approximate the texture, flavor and/or nutrient profiles of conventional animal meat. These novel plant-based meat alternatives, enabled by advances in food technology, can be fundamentally different from the whole-plant foods from which they are derived. One of the reasons is the necessity to use food additives on various occasions, since consumers' acceptance of plant-based meat products primarily depends on the organoleptic properties. Consequently, a high degree of heterogeneity in formulation and nutritional profiles exists both within and between product categories of plant-based meat alternatives with unknown effects on several aspects of human health. This is further complicated by the differences in digestibility and bioavailability between proteins from animal and plant sources, which have a profound impact on colonic fermentation, nutritional adequacy and potential health effects. On the other hand, emerging strategies provide opportunities to develop affordable, delicious and nutritious plant-based meat alternatives that align with consumer interests.

Preparation of Whole-Cut Plant-Based Pork Meat and Its Quality Evaluation with Animal Meat

Low-moisture (20~40%) and high-moisture (40~80%) textured vegetable proteins (TVPs) can be used as important components of plant-based lean meat, while plant-based fat can be characterized by the formation of gels from polysaccharides, proteins, etc. In this study, three kinds of whole-cut plant-based pork (PBP) were prepared based on the mixed gel system, which were from low-moisture TVP, high-moisture TVP, and their mixtures. The comparisons of these products with commercially available plant-based pork (C-PBP1 and C-PBP2) and animal pork meat (APM) were studied in terms of appearance, taste, and nutritional qualities. Results showed the color changes of PBPs after frying were similar to that of APM. The addition of high-moisture TVP would significantly improve hardness (3751.96~7297.21 g), springiness (0.84~0.89%), and chewiness (3162.44~6466.94 g) while also reducing the viscosity (3.89~10.56 g) of products. It was found that the use of high-moisture TVP led to a significant increase in water-holding capacity (WHC) from 150.25% to 161.01% compared with low-moisture TVP; however, oil-holding capacity (OHC) was reduced from 166.34% to 164.79%. Moreover, essential amino acids (EAAs), the essential amino acids index (EAAI), and biological value (BV) were significantly increased from 272.68 mg/g, 105.52, and 103.32 to 362.65 mg/g, 141.34, and 142.36, respectively, though in vitro protein digestibility (IVPD) reduced from 51.67% to 43.68% due to the high-moisture TVP. Thus, the high-moisture TVP could help to improve the appearance, textural properties, WHC, and nutritional qualities of PBPs compared to animal meat, which was also better than low-moisture TVP. These findings should be useful for the application of TVP and gels in plant-based pork products to improve the taste and nutritional qualities.

Effects of Food Factors and Processing on Protein Digestibility and Gut Microbiota

Protein is an essential macronutrient. The nutritional needs of dietary proteins are met by digestion and absorption in the small intestine. Indigestible proteins are further metabolized in the gut and produce metabolites via protein fermentation. Thus, protein indigestibility exerts a wide range of effects on gut microbiota composition and function. This review aims to discuss protein digestibility, the effects of food factors, such as protein sources, intake level, and amino acid composition, and making meat analogues. Besides, it provides an inventory of antinutritional factors and processing techniques that influence protein digestibility and, consequently, the diversity and composition of intestinal microbiota. Future studies are warranted to understand the implication of plant-based analogues on protein digestibility and gut microbiota and to elucidate the mechanisms concerning protein digestibility to host gut microbiota using various omics techniques.

Influence of hemin on structure and emulsifying properties of soybean protein isolate

Hemin has potential application value in plant-based meat analogues. However, mechanisms of interaction between hemin and plant protein are unclear. In this study, soy protein isolate (SPI) was applied to examine these interactions using multi-spectroscopic and molecular docking techniques. Additionally, the influence of hemin on emulsification of SPI was also explored. Fluorescence and UV-Vis spectra showed quenching of SPI by hemin was static, resulting in conformation changes on the surface amino acid residues, around which hydrophobicity was significantly reduced from 425.9 ± 16.2 to 108.9 ± 1.8 (p < 0.05). FTIR and CD spectra results suggested the protein secondary structure altered, and the content of α-helix and random coils increased by 1.13% and 1.43%, respectively. Furthermore, emulsifying properties of SPI were strengthened with increased hemin. This work improves our understanding of interactions between SPI and hemin and offer a theoretical basis for application of heme in plant-based meat analogues.