Some biochemical studies on trans fatty acid-containing diet

Chronic trans fatty acid consumption shortens lifespan in male Drosophila melanogaster on a high-sugar and high-fat diet

Aging entails the progressive decline in the body's self-regulation and functionality over time. Notably, obesity and aging exhibit parallel phenotypes, with obesity further accelerating the aging process across multiple dimensions and diminishing lifespan. In this study, we explored the impact of trans fatty acid (TFA) consumption on the overall health and lifespan of male Drosophila melanogaster under an isocaloric high-sugar and high-fat diet. Our results indicate that TFA intake results in a shortened lifespan, elevated body weight, and increased triglyceride levels in flies fed a high-sugar and high-fat diet with equivalent caloric intake. Additionally, TFA exposure induces oxidative stress, locomotor deficits, and damage to the intestinal barrier in flies. Collectively, chronic TFA consumption expedites the aging process and reduces the lifespan of male Drosophila melanogaster. These results contribute supplementary evidence regarding the adverse health effects associated with TFAs.

A study on the configuration of factors influencing overweight and obesity in adolescents based on fuzzy set qualitative comparative analysis

OBJECTIVE

Overweight and obesity among adolescents are grave public health issues around the world. Although the conditions that contribute to obesity have been extensively researched, little is known about how multiple conditions interact to cause overweight and obesity. The current study intends to investigate the histomorphic configuration pathways of several conditions of adolescent overweight and obesity by gender.

METHOD

The data came from a social survey conducted in June 2021 in Changchun, Jilin Province, China. The sample collected was 14-year-old adolescents, including 167 boys and 137 girls. The school physicians examined the participants' weight and height, and questionnaires were used to collect risk indicators from adolescents, such as sleep duration, electronic screens times, consumption of sugary drinks and fried foods, and physical activity. Simultaneously, a Fuzzy Qualitative Comparative Analysis will be performed to investigate the combinations of diverse conditions.

RESULT

We found that there is no determining necessary condition that, once present, directly determines that an individual is in a state of overweight and obesity. Simultaneously, this study revealed nine alternative configurational paths of overweight and obesity in teenagers of different genders, with a concordance of 0.805 for six male groupings and 0.916 for three female groupings. The outcomes of overweight obesity in adolescents under different genders are similar but not identical.

CONCLUSION

This study examined the interactions of a number of conditions from the individual, behavioral, learning and living environment that led to the same overweight obese outcome among adolescents of different genders. Our research will be useful to policymakers in that interventions should take into account the combined effects of a number of different aspects rather than focusing on a single factor that causes overweight and obesity.

Low intake of ruminant trans fatty acids ameliorates the disordered lipid metabolism in C57BL/6J mice fed a high-fat diet

Currently, the health benefits of ruminant trans fatty acids (R-TFA) are still controversial. Our previous investigations indicated that R-TFA at higher dosages (1.3% and 4% E) caused disordered lipid metabolism in mice; however, through collecting R-TFA intake data in 9 provinces of China, it was suggested that, in 2021, the range of R-TFA intake for Chinese residents was about 0.053-0.307 g d-1. Based on the 2022 Nutritional Dietary Guidelines for Chinese Residents, the recommended daily energy supply from R-TFA was about 0.11%-0.15% E. However, the health effects of R-TFA at a lower dosage are still unknown; therefore, our current research aims to further explore the effects of R-TFA on health. Through in vivo experiments, it was shown that R-TFA (0.15% E) decreased body weight gain and serum cholesterol levels in C57BL/6J mice fed a high-fat diet, while it had no significant effect on mice fed a low-fat diet. Besides, hepatic histopathology analysis suggested that R-TFA (0.15% E) ameliorated the degree of hepatic steatosis and reduced intrahepatocyte lipid droplet accumulation in C57BL/6J mice fed a high-fat diet. Through lipidomics analysis, we further screened 8 potential lipid metabolites that participate in regulating the dysregulation of lipid metabolism. Finally, it was suggested that R-TFA (0.15% E) down-regulated the expression of genes related to inflammation and cholesterol synthesis while up-regulated the expression of genes related to cholesterol clearance, which might partially explain the salutary effect of R-TFA (0.15% E) in ameliorating the hepatic steatosis and improving disordered lipid metabolism in mice fed a high-fat diet. Our current research will provide a reference for the intake of R-TFA and, furthermore, give some insights into understanding the health effects of R-TFA.

Integration of hepatic lipidomics and transcriptomics reveals the effect of butter-derived ruminant trans fatty acids on lipid metabolism in C57BL/6J mice

Dysregulation of lipid metabolism results in metabolism-related diseases. Our previous research indicated that 1.3% E and 4% E ruminant trans fatty acids (R-TFA) caused dyslipidemia and promoted atherosclerotic plaques in ApoE-/- mice, presenting detrimental effects. However, the effect of R-TFA on the lipid metabolism of normal mice remains unclear. Therefore, our current research aims to explore the effects of butter-derived R-TFAs on the lipid metabolism of C57BL/6J mice through the integration of lipidomics and transcriptomics. As a result, we found that 1.3% E butter-derived R-TFA promoted dyslipidemia and impaired hepatic function in C57BL/6J mice fed a high-fat diet, which was associated with an increase in DG (18:1/22:5), TG (18:1/18:2/22:4) and FA (24:5) as determined through lipidomics analysis, but had a less significant effect on C57BL/6J mice fed a low-fat diet. Through a combination analysis and verification of gene expression, we found that the arachidonic acid pathway might be involved in the disruption of lipid metabolism by butter-derived R-TFA. In addition, butter-derived R-TFA up-regulated the expression of unigene thromboxane-A synthase 1 (Tbxas1), arachidonate lipoxygenase 3 (Aloxe3), acyl-coenzyme A thioesterase 2 (Acot2), epoxide hydrolase 2 (Ephx2) and carbonyl reductase 3 (Cbr3) in C57BL/6J mice fed a high-fat diet. Herein, our research provides a new perspective for exploring the effects of butter-derived R-TFA on lipid metabolism and speculates on the possible mechanism of lipid metabolism disorder induced by butter-derived R-TFA in C57BL/6J mice fed a high-fat diet.

Exposure to trans fat during the developmental period ofDrosophila melanogasteralters the composition of fatty acids in the head and induces depression-like behavior

Given the importance of understanding the disorders caused by trans fatty acids (TFAs), this study sought to add different concentrations hydrogenated vegetable fat (HVF) to the diet of Drosophila melanogaster during the developmental period and evaluate the effects on neurobehavioral parameters. Longevity, hatching rate, and behavioral functions were assessed, such as negative geotaxis, forced swimming, light/dark, mating, and aggressiveness. The fatty acids (FAs) present in the heads of the flies were quantified as well as serotonin (5HT) and dopamine (DA) levels. Our findings showed that flies that received HVF at all concentrations during development showed reduced longevity and hatching rates, in addition to increased depression-like, anxious-like, anhedonia-like, and aggressive behaviors. As for the biochemical parameters, there was a more significant presence of TFA in flies exposed to HVF at all concentrations evaluated and lower 5HT and DA levels. This study shows that HVF during the developmental phase can cause neurological changes and consequently induce behavioral disorders, thereby highlighting the importance of the type of FA offered in the early stages of life.

C57bl/6 Mice Show Equivalent Taste Preferences toward Ruminant and Industrial Trans Fatty Acids

Two distinct types of trans fatty acids (TFA) are found in the diet. Industrial TFA such as elaidic acid (EA) have deleterious effects on metabolic risk factors, and oppositely ruminant TFA including trans-palmitoleic acid (TPA) may have beneficial effects. The objective is to evaluate the taste preference between EA, TPA, lecithin or water. In this study, 24 female C57BL/6 mice were microchipped and placed in two separate IntelliCages^®. Nano encapsulated TFA or lecithin were added to drinking water in different corners of the cage with normal diet. The study was carried out over 5 weeks, during which mice were exposed to water only (weeks 1 and 3), TFA or lecithin (week 2), and EA or TPA (weeks 4 and 5). Mice weights, corner visits, nose pokes (NP), and lick number were measured each week. The results demonstrated that mice consume more TFA, either EA or TPA, compared with lecithin. In addition, the mice licked more EA compared with TPA in one cage; conversely, in the other cage they licked more TPA compared with EA. However, when TFA positions were swapped, mice had equal licks for EA and TPA. In sum, mice preferred TFA, in equal matter compared with controls; therefore, the results demonstrate the potential for TFA-type substitution in diet.

Microencapsulation protects the biological activity of sea buckthorn seed oil

Introduction

Sea buckthorn (Hippophae rhamnoides) seed oil is rich in unsaturated fatty acids, and is thus susceptible to oxidation and rancidity. Microencapsulation technology allows the effective protection of active substances, thereby prolonging the deterioration time and shelf life.

Methods

In this study, H. rhamnoides microcapsules were prepared using a spray-drying method, and the microencapsulation parameters were optimized. The morphological characteristics, structural parameters, and stability of the microcapsules were determined using scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and oil oxidation stability testing.

Results

Based on encapsulation efficiency (EE, %) and the particle size (D50) of the microcapsules, the optimal preparation conditions were characterized as a wall material consisting of soy protein isolate and soybean polysaccharide (2:3), a wall concentration of 15%, a core-to-wall ratio of 1:3, and an inlet temperature of 160°C. Under these optimal conditions, the encapsulation efficiency was 95.30 ± 2.67%, with a yield of 57.03 ± 3.71% and a particle size of 7.96 ± 1.04 μm.

Discussion

Furthermore, the effectiveness of microencapsulation in protecting the biological activity of H. rhamnoides seed oil was confirmed by an antioxidation test. Thus, the results of this study showcase the successful microencapsulation of H. rhamnoides seed oil, thereby significantly improving its stability.

New research development on trans fatty acids in food: Biological effects, analytical methods, formation mechanism, and mitigating measures

The trans fatty acids (TFAs) in food are mainly generated from the ruminant animals (meat and milk) and processed oil or oil products. Excessive intake of TFAs (>1% of total energy intake) caused more than 500,000 deaths from coronary heart disease and increased heart disease risk by 21% and mortality by 28% around the world annually, which will be eliminated in industrially-produced trans fat from the global food supply by 2023. Herein, we aim to provide a comprehensive overview of the biological effects, analytical methods, formation and mitigation measures of TFAs in food. Especially, the research progress on the rapid, easy-to-use, and newly validated analytical methods, new formation mechanism, kinetics, possible mitigation mechanism, and new or improved mitigation measures are highlighted. We also offer perspectives on the challenges, opportunities, and new directions for future development, which will contribute to the advances in TFAs research.

Determination of the fatty acid composition and fatty acids trans-isomers in the horse, stall horse, mutton, beef and pork meat

In this study, we have focussed on the fatty acid composition of the meat of various animals raised in the Republic of Kazakhstan. We have analyzed pasture horse meat, stall horse meat, lamb, beef, and pork meat. Samples from four carcass muscles (back, hip, rib, and neck) were tested. Comparative analysis of the content of trans isomers of fatty acids (TFA) was performed. The analysis of the obtained samples showed that the TFA content is significantly (p <0.05) different in different parts of the carcasses of all animals. Their highest content was observed in the mutton sample, which reached 79.56-82.04%. The beef was next after mutton (6.20-9.64%). Less than in mutton and beef, but more than in pork and TFAs were contained in stall horse meat (2.75-5.52%). Of the two types of horse meat, there was less TFA in horse meat of pasture content (1.85-3.46%). Compared to all studied samples, the lowest level of trans fatty acids was in pork (0.91-1.39%). In horse meat of both types, TFAs were present in trans-9-C16: 1. More types of TFA were found in the meat of other animals: in mutton (trans-9-C14: 1; trans-9-C16: 1; trans-9-C18: 1; trans-11 C18: 1; trans-9-trans- 12-C18: 2), in beef (trans-9-C16: 1; trans-9-C18: 1; trans-11-C18: 1; trans-9-trans-12-C18: 2), in pork (trans-9-C16: 1). In addition to TFA, an analysis was made of the ratio of omega-6 and omega-3 (ω-6: ω-3). Considering that the lower the ratio of ω-6: ω-3 in fat, the healthier it is for the human body, the most optimal among the studied samples in terms of the ratio of ω-6: ω-3 fatty acids was mutton (1.83-2.35) and horse meat of stall keeping (1.76-6.53). The most unfavourable ratios were in the pork samples (17.46-35.69). The ratio ω-6: ω-3 in other animals was within the following limits: beef (5.35-9.13), horse meat of pasture content (7.08-10.50).

Dietary Ruminant and Industrial Trans-Fatty Acids Intake and Colorectal Cancer Risk

As colorectal cancer (CRC) is largely due to modifiable lifestyle habits, the awareness on its risk factors is highly important. Dietary fatty acids have been linked to CRC risk. We explored the association between dietary trans fatty acids (TFAs) intake and CRC risk. We analyzed 865 CRC cases (434 in colon and 404 in rectum) and 3206 controls of the IROPICAN study, with data collected by trained interviewers using validated questionnaires. TFAs intake (industrial and ruminant types) was categorized into quartiles. Multivariate logistic regression models were built to calculate the odds ratios (OR) for the association between CRC and TFAs. We observed a positive association between industrial TFAs and colon cancer (OR for highest vs lowest quartile [ORQ4vsQ1] = 1.28, 95% confidence interval 1.07-1.54). A higher association was observed between industrial TFAs and CRC, occurring after 50 years of age. In addition, elaidic acid was associated with an increased risk of colon (ORQ4vsQ1 = 1.58, 1.24-2.02) and specifically of proximal colon cancer (OR Q4vsQ1 = 2.12, 1.40-3.20), as well as of rectum cancer (ORQ4vsQ1 = 1.40, 1.07-1.83). An inverse association was observed between ruminant TFAs intake and colon cancer risk (ORQ4vsQ1 = 0.80, 0.67-0.97). Industrial TFAs, such as semisolid/solid hydrogenated oils, may increase the risk of CRC, especially colon and proximal colon cancer. In contrast, ruminant TFAs do not appear to be associated with CRC. Awareness programs and regulatory actions regarding hydrogenated oils are warranted, given their high consumption through ultra-processed foods in more developed and less developed countries.

High-fat diets containing different types of fatty acids modulate gut-brain axis in obese mice

Background

Excessive consumption of high-fat diets is associated with disordered metabolic responses, which may lead to chronic diseases. High-fat diets containing different types of fatty acids lead to distinct alterations in metabolic responses of gut-brain axis.

Methods

In our study, normal male C57BL/6J mice were fed to multiple high fatty acid diets (long-chain and medium-chain saturated fatty acid, LCSFA and MCSFA group; n-3 and n-6 polyunsaturated fatty acid, n-3 and n-6 PUFA group; monounsaturated fatty acid, MUFA group; trans fatty acid, TFA group) and a basic diet (control, CON group) for 19 weeks. To investigate the effects of high-fat diets on metabolic responses of gut-brain axis in obese mice, blood lipids were detected by fast gas chromatography, and related proteins in brain and intestine were detected using Western blotting, ELISA, and immunochemistry analysis.

Results

All high-fat diets regardless of their fatty acid composition induced obesity, lipid disorders, intestinal barrier dysfunction, and changes in gut-brain axis related factors except basal diet in mice. For example, the protein expression of zonula occludens-1 (ZO-1) in ileum in the n-3 PUFA group was higher than that in the MCSFA group (P < 0.05). The expressions of insulin in hippocampus and leptin in ileum in the MCSFA group significantly increased, compared with other groups (all Ps < 0.05).

Conclusion

The high MCSFA diet had the most effect on metabolic disorders in gut-brain axis, but the high n-3 PUFA diet had the least effect on changes in metabolism.

Sugar, salt and fat reduction of bakery products

From the health viewpoint, consumers monitor their food uptake in terms of both quality and quantity, due to awareness of the link between food ingredients and health. Accordingly, many people tend to buy healthy food products that are low in or free of sugar, salt and fat. However, in baked products, the sugar, fat and salt are needed to create unique characteristics. The role of sugar, salt and fat in baked products is discussed in this chapter to understand their functions. The understanding is necessary to design proper techniques to reduce the amount of sugar, salt and fat. Ingredients and additives that can substitute for fat, sugar and salt in bakery characteristics are reviewed in terms of their advantages and disadvantages. In addition, alternative processes to reduce the use of fat, sugar and salt are proposed in this chapter.

Olive Oil Improves While Trans Fatty Acids Further Aggravate the Hypomethylation of LINE-1 Retrotransposon DNA in an Environmental Carcinogen Model

DNA methylation is an epigenetic mechanism that is crucial for mammalian development and genomic stability. Aberrant DNA methylation changes have been detected not only in malignant tumor tissues; the decrease of global DNA methylation levels is also characteristic for aging. The consumption of extra virgin olive oil (EVOO) as part of a balanced diet shows preventive effects against age-related diseases and cancer. On the other hand, consuming trans fatty acids (TFA) increases the risk of cardiovascular diseases as well as cancer. The aim of the study was to investigate the LINE-1 retrotransposon (L1-RTP) DNA methylation pattern in liver, kidney, and spleen of mice as a marker of genetic instability. For that, mice were fed with EVOO or TFA and were pretreated with environmental carcinogen 7,12-dimethylbenz[a]anthracene (DMBA)-a harmful substance known to cause L1-RTP DNA hypomethylation. Our results show that DMBA and its combination with TFA caused significant L1-RTP DNA hypomethylation compared to the control group via inhibition of DNA methyltransferase (DNMT) enzymes. EVOO had the opposite effect by significantly decreasing DMBA and DMBA + TFA-induced hypomethylation, thereby counteracting their effects.

Dietary fatty acids affect learning and memory ability via regulating inflammatory factors in obese mice

OBJECTIVE

High-fat diets are linked to obesity, contributing to the alterations in inflammatory signaling pathways, which is associated with cognitive function. We aim to investigate the mechanisms by which various different types of dietary fatty acids affecting cognitive function in obese mice through the gut/brain axis-inflammatory signaling pathway.

METHODS AND RESULTS

Eight-week-old male C57BL/6 mice were fed with basal diet (control group), lard high-fat diet (containing long-chain saturated fatty acid (LCSFA group)), coconut oil high-fat diet (containing medium-chain saturated fatty acid (MCSFA group)), linseed oil high-fat diet (containing n-3 polyunsaturated fatty acid (n-3 PUFA group)), soybean oil high-fat diet (containing n-6 polyunsaturated fatty acid (n-6 PUFA group)), olive oil high-fat diet (containing monounsaturated fatty acid (MUFA group)) and 8% hydrogenated soybean oil high-fat diet (containing trans fatty acid (TFA group)) respectively for 16 weeks. Our results revealed that the mean escape latency was significantly prolonged in LCSFA group, and the latency to cross the platform location of n-6 PUFA and TFA groups were increased significantly. The differences of inflammatory markers and toll-like receptor-myeloid differentiation factor-88-nuclear factor kappa-B (TLR-MyD88-NF-κB) inflammatory signaling pathway expressions among all groups reached statistical significances.

CONCLUSION

Compared to basal diet, high-fat diets enriched in LCSFA, MCSFA, n-6 PUFA, MUFA, and TFA might exert detrimental effects on cognitive function in obese mice via regulating the inflammatory markers and inflammatory signaling pathway in brain and intestine. High-fat diet enriched in n-3 PUFA might exhibit different effect on modulating inflammatory responses in different tissues and might benefit to cognitive function.

Bioinspired organohydrogels with heterostructures: Fabrications, performances, and applications

Since emerging in 1960, the artificial hydrogels have garnered enormous attentions in scientific community due to their high level of similarities to biological soft tissues in both structures and properties. With the proceeding of research, the concern of hydrogels is gradually shifted from fundamental investigation to abundant functionalization. In contrast to the natural soft tissues, the current artificial hydrogels still possess relatively simple structures and unsatisfactory environmental adaptability, extremely limiting their practical applications in complex environments. Enlightened by the prominent adaptability of biological organisms, the binary cooperative complementary principle is utilized to develop bioinspired organohydrogels by combining two components with opposite but cooperative physiochemical features. The present review provides the advanced progresses of bioinspired organohydrogels with sophisticated heterogeneous networks and desirably environmental adaptabilities. We clearly summarize the synthesizing strategies in regard to both corresponding mechanisms and typical examples, including macroscopic organohydrogels, organohydrogels with binary solvent, organohydrogels with heteronetworks, and emulsion-based organohydrogels. Meanwhile, the intriguing features of the reported organohydrogels, such as temperature resistance, switchable mechanics, adaptive wettability, and opposite components compatibility, are also clearly highlighted with a short overview of their promising applications. Ultimately, the current challenges and perspectives on the future development of bioinspired organohydrogels are also discussed.

Longitudinal association between an overall diet quality index and latent profiles of cardiovascular risk factors: results from a population based 13-year follow up cohort study

BACKGROUND

Cardiovascular diseases (CVDs) are associated with an unhealthy lifestyle, including poor diet. Indices reflecting the overall quality of diets are more effective than single food or nutrient-based approaches in clarifying the diet disease relationship. The present study aims to use latent variable modeling to examine the longitudinal joint relationships between the latent profiles of CVDs risk factors and the diet quality index (DQI).

METHODS

A total of 4390 Iranian adults aged 35 and older within the framework of the Isfahan Cohort Study were included in the current secondary analysis. DQI focused on food groups, including fast foods, sweets, vegetables, fruits, fats, and proteins, based on a validated food frequency questionnaire. The score of DQI has a range between 0 (indicating healthy and high diet quality) and 2 (indicating unhealthy and low diet quality). Blood pressure (BP), anthropometric measurements, blood glucose, serum lipids, and high-sensitivity C-Reactive Protein (hs-CRP) were measured according to standard protocols in 2001, 2007, and 2013 to evaluate the profiles of CVDs risk factors. A Bayesian Multidimensional Graded Responses Linear Mixed Model was used for data analysis.

RESULTS

At baseline, the participants' mean ± standard deviation age was 50.09 ± 11.21, and 49.5% of them were male. Three latent profiles of CVDs risk factors were derived: (1) Fit Pre-Metabolic Syndrome (FPMS) profile characterized by normal anthropometric indices and some impaired metabolic risk factors; (2) DysLipoproteinemia Central Obese (DLCO) profile with abdominal obesity and impaired low-density lipoprotein cholesterol as well as other normal risk factors; (3) Impaired Laboratory Inflammatory State (ILIS) profile with impaired high-density lipoprotein cholesterol and hs-CRP and other normal risk factors. In general, higher scores of the extracted latent profiles indicated more impaired function in the related risk factors. After controlling for various potential fixed and time-varying confounding variables, a significant positive longitudinal association was found between FPMS, DLCO, and ILIS profiles and DQI (β (95% CrI): 0.26 (0.03,0.51), 0.14 (0.01,0.27), and 0.24 (0.11,0.38), respectively), demonstrating that lower overall diet quality was associated with more impaired function of the related risk factors.

CONCLUSIONS

More adherence to a healthy quality diet is associated with lower levels of all emerging latent profiles of CVDs risk factors. Increasing the knowledge of the community about the importance of the quality of consumed foods may help to prevent CVDs. It is recommended that further investigations, particularly interventional studies, be conducted to confirm our results.

Fabrication of OSA Starch/Chitosan Polysaccharide-Based High Internal Phase Emulsion via Altering Interfacial Behaviors

This paper attempted to construct a high internal phase emulsion (HIPE) through altering interfacial behaviors using the electrostatic interaction between positive chitosan and negative octenyl succinic anhydride (OSA) starch. The partial polysaccharide complex of OSA starch/chitosan was used to stabilize HIPE, which was able to adsorb at the oil droplet interface and prevent the coalescence of oil droplets. The wettability of OSA starch was enhanced with the addition of positively charged chitosan, leading to the formation of partial complexes. The impact of pH and concentration of chitosan on the droplet size, surface charge, and interface behavior were investigated, and the formation of the polysaccharide complex was further confirmed by atomic force microscopy. The presence of the OSA starch/chitosan complex facilitated the formation of stable HIPE with a gel-like structure and satisfactory centrifugal and oxidative stability. These results are useful to provide information for fabricating polysaccharide-based HIPE delivery systems, which may help expand their application in the food industry.

Dietary Fat-Accelerating Leptin Signaling Promotes Protumorigenic Gastric Environment in Mice

Excess of fat intake leads to obesity and causes a variety of metabolic diseases and cancer. We previously demonstrated that high-lard diet induces intestinal metaplasia, a precancerous lesion of the stomach mediated by leptin signaling. This study aims to investigate which kinds of dietary fat cause the intestinal metaplasia onset. We fed eight kinds of high-fat diets (HFDs) of animal or plant origin to mice evaluated their effect on gastric pathogenesis. Five types of dietary fat were divided according to their observed effects: Obese with high metaplasia (group I; beef tallow, lard, and hydrogenated coconut oil), non-obese with high metaplasia (group II; linseed oil), obese without metaplasia (group III; corn oil and olive oil), non-obese without metaplasia (group IV, soybean oil) and lean without metaplasia (group V; cocoa butter). The group I and II diets induced leptin, phosphorylated leptin receptor (ObR), signal transducer and activator 3 (STAT3), and increased intracellular β-catenin accumulation in the stomach. Moreover, mice fed these HFDs with 1-methyl-3-nitro-1-nitrosoguanidine (MNNG), a gastric carcinogen, and further accelerated dysplasia in the stomach. Lactobacillus occupancy in the stomach increased in all HFDs except hydrogenated coconut oil. Our findings suggest that HFDs inducing leptin signaling accelerate the enhancement of protumorigenic gastric microenvironment independent of body mass gain or microbiome changes.