Diet Selection Research Articles

Next-generation diabetes diagnosis and personalized diet-activity management: A hybrid ensemble paradigm.

Diabetes, a chronic metabolic condition characterised by persistently high blood sugar levels, necessitates early detection to mitigate its risks. Inadequate dietary choices can contribute to various health complications, emphasising the importance of personalised nutrition interventions. However, real-time selection of diets tailored to individual nutritional needs is challenging because of the intricate nature of foods and the abundance of dietary sources. Because diabetes is a chronic condition, patients with this illness must choose a healthy diet. Patients with diabetes frequently need to visit their doctor and rely on expensive medications to manage their condition. It is challenging to purchase medication for chronic illnesses on a regular basis in underdeveloped nations. Motivated by this concept, we suggest a hybrid model that, rather than depending solely on medication to evade a visit to the doctor, can first anticipate diabetes and then suggest a diet and exercise regimen. This research proposes an optimized approach by harnessing machine learning classifiers, including Random Forest, Support Vector Machine, and XGBoost, to develop a robust framework for accurate diabetes prediction. The study addresses the difficulties in predicting diabetes precisely from limited labeled data and outliers in diabetes datasets. Furthermore, a thorough food and exercise recommender system is unveiled, offering individualized and health-conscious nutrition recommendations based on user preferences and medical information. Leveraging efficient learning and inference techniques, the study achieves a meager error rate of less than 30% using an extensive dataset comprising over 100 million user-rated foods. This research underscores the significance of integrating machine learning classifiers with personalized nutritional recommendations to enhance diabetes prediction and management. The proposed framework has substantial potential to facilitate early detection, provide tailored dietary guidance, and alleviate the economic burden associated with diabetes-related healthcare expenses.

Most relevant microhistological characters of Cistus species for herbivore diet determination

ABSTRACT The genus Cistus plays a crucial role in the Mediterranean ecosystems. However, studies on microhistological characters of its leaves are scarce, resulting in a knowledge gap. We focused here on all Cistus species in the eastern Sierra Morena, southern Iberian Peninsula: C. albidus, C. crispus, C. ladanifer, C. laurifolius, C. monspeliensis, C. populifolius and C. salviifolius, because these species are present in the diet of ruminant herbivores such as deer. Our study involved analysing, characterizing, and comparing trichomes, stomata and epidermal cells, with a total of 17 variables analysed. The results confirm the distinction of Cistus species based on microhistological characteristics. Understanding these structures facilitates taxonomic classification and analysis of wild ungulate diet and habitat selection using light microscopy. We generate a helpful resource for future micro-histological analysis studies applied to wild ungulate diets determination, botany, conservation biology and resources management.

Morphometric Study on the Mandible of Colobine Fossil (Mesopithecus pentelicus) Found in East Asia, a Comparison With Extant Taxa.

A tooth-bearing mandible fossil of a colobine monkey discovered at Shuitangba, Zhaotong, Yunnan, China, was morphometrically analyzed and compared with extant Asian colobines. Our previous qualitative and quantitative descriptions indicate that it can be safely attributed to Mesopithecus pentelicus, a Miocene fossil colobine widely found in Europe and South Asia. The present research aims to explore fossil association with extant colobines and functionally propose its dietary preferences based on multivariate morphometric analyses of mandibular morphology. The results indicate that this fossil species presents a mosaic association with extant langurs (Presbytis, Trachypithecus, and Semnopithecus) and odd-nosed monkeys (Pygathrix, Nasalis, and Rhinopithecus), with most similarities of size-related traits and size-adjusted shapes, and a notable difference from extant Rhinopithecus, due to the increased body size of the latter since the Pliocene. The allometric analysis showed that, like the fossils of the same species in other sites, its mandibular structure appears more adapted to crushing hard seed shells than chewing leaves. Moreover, our findings also imply that the Asian colobines significantly modified their dietary preferences over the last 6 million years following the ecological and environmental changes triggered by the accelerated uplift of the Qinghai-Tibet Plateaus and severe monsoons. Morphologically, the more developed condyle length and moment arms of the temporomandibular joint and medial pterygoid muscles appear to accommodate a more folivorous dietary selection, functionally related to the intake of rigid fibers in leaves that require frequent one or two-side mandibular chewing and grinding.

Trophic ecology of the clingfish Gobiesox marmoratus (Gobiesocidae): experimental evaluation of constraints to foraging behaviour

ABSTRACT The Chilean clingfish Gobiesox marmoratus Jenyns (Gobiesocidae) is a common carnivorous fish inhabiting the rocky intertidal pools along the Chilean coast. In spite of its wide-ranging distribution, basic knowledge about this species is scarce and as a consequence important aspects of its biology such as dietary composition, dietary selectivity and trophic behaviour have received little attention. The goals of this work were to assess quantitatively the dietary composition of this species, its trophic selectivity, assimilation rate of its prey and to experimentally analysed the role of the prey energy value, pre-digestive and post-digestive limitations in the dietary selection of this species. The diet of this species is mainly based on invertebrates, particularly amphipods, crabs and limpets as the most important food items. In laboratory, crabs and amphipods were the most preferred and consumed items over limpets and snails. Our results show that the amphipod is the prey item that provides to G. marmoratus with greater energy per unit of time of manipulation, which would explain its preference in the laboratory experiments and suggests that G. marmoratus feeds according to the net energy gain of their prey, supporting energy maximization, an underlying assumption of foraging theory.

Picky eaters: Selective microbial diet of avian ectosymbionts.

Individual organisms can function as ecosystems inhabited by symbionts. Symbionts may interact with each other in ways that subsequently influence their hosts positively or negatively, although the details of how these interactions operate collectively are usually not well understood. Vane-dwelling feather mites are common ectosymbionts of birds and are proposed to confer benefits to hosts by consuming feather-degrading microbes. However, it is unknown whether these mites exhibit generalist or selective diets, or how their dietary selection could potentially impact their symbiotic functional nature. In this study, we conducted 16S rDNA and ITS1 amplicon sequencing to examine the microbial diet of feather mites. We characterized and compared the diversity and composition of bacteria and fungi in the bodies of mites living on feathers of the Prothonotary Warbler, Protonotaria citrea, to microbial assemblages present on the same feathers. We found less diverse, more compositionally similar microbial assemblages within mites than on feathers. We also found that mites were resource-selective. Based on the identity and known functions of microbes found within and presumably preferred by mites, our results suggest that these mites selectively consume feather-degrading microbes. Therefore, our results support the proposition that mites confer benefits to their hosts. This study provides insight into symbioses operating at multiple biological levels, highlights the ecological and evolutionary importance of the synergistic interactions between species, and greatly expands our understanding of feather mite biology.

Factors influencing the variability in performance of cattle grazing tropical pasture

Context Whereas it is known that there is variation in liveweight gain (described as performance in this paper) within a group of grazing cattle, the causes of this variation are not well understood. Aim A 2-year grazing study in northern Queensland was conducted to understand the relative influence of diet selection, grazing behaviour and rumen fermentation on variation in performance of growing cattle. Methods Eighty-nine Bos taurus × B. indicus (~6 months old) growing steers were grazed as a group on mixed tropical pasture for 23 months. Pasture was characterised for biomass, species and nutrient composition. Cattle were ranked according to overall liveweight (LW) gain and the top (high performance, HP) 20 and bottom (low performance, LP) 20 head were compared for diet composition, rumen fermentation and grazing behaviours. Results Pasture biomass, and nutritive value of pasture and diet varied between seasons and years of study. The HP cattle achieved overall LW gains 20% greater than those of the LP cattle mainly due to higher rates of gain in the wet season. However, the nutritive value and rumen fermentation characteristics were similar for both LP and HP cattle, although there was evidence that crude protein and digestibility were modestly higher in diets of HP cattle, especially in the first wet season. Activity, measured as distance travelled, declined as pasture biomass declined, and cattle appeared to favour pasture with higher legume content. Conclusion It is concluded that divergence in performance of cattle on tropical pasture could not be fully explained by measurements taken in this study. Diet selection for plant components with improved nutritive value probably played a small role. Differences in initial LW between the LP and HP groups may have been a contributory factor. Implications Despite comprehensive measurements of factors that influence efficiency and performance on pasture, we were unable to identify definitive causes. Genetic variation in feed intake or efficiency of digestion needs to be investigated.

Lambs Grazing With Adult Ewes Prefer Forbs With High-Nutrient Content in Native Grasslands Dominated by Leymus chinensis and Stipa grandis.

Grazing livestock in grasslands face the challenge of obtaining sufficient nutrition due to uneven distribution of plant species and fluctuating vegetation productivity and nutrient levels. In northern China, Leymus chinensis and Stipa grandis are the dominant perennial species in native grasslands, but they provide limited nutrition compared to forbs with higher crude protein (CP) content. While dietary ingredients can affect the nutritional intake of grazing livestock, the influence of different grazing strategies on dietary selection remains unclear. In this study, three sheep grazing strategies (lambs alone, mixed lambs and ewes, and ewes alone) were used to explore dietary selection. We investigated the influence of vegetation characteristic (above-ground biomass production, height, and species diversity) and foraging behavior (feed intake, organic matter digestibility, and daily grazing time) on the mechanisms of dietary selection (taxonomic family richness and composition). Forage consumption across the grazing strategies revealed that species from Poaceae, Rosaceae, and Cyperaceae families were frequently consumed. Both ewes and lambs in the mixed-grazing strategy preferentially consumed forbs with diverse species composition (Jacob's D > 0), which contained higher CP than those available in the overall vegetation (p < 0.05). In addition, dietary richness was significantly (p < 0.05) influenced by vegetation species diversity except for animals in the lambs alone strategy. Compared to lambs in mixed-grazing, lambs alone had both greater daily grazing time and consumption of grass with lower digestibility (p < 0.05). Our study is the first to demonstrate that lambs can develop a similar dietary selection and behavioral pattern when grazing with adult ewes in temperate grasslands. Our study indicates that the conservation of species diversity in native grasslands is critically beneficial to livestock nutrition.

Exploring the effect of diet programs on the behavior of Sudanese children with autism and the prevalence and association of gastrointestinal symptoms: a multi-center cross-sectional study.

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterized by social difficulties, speech and nonverbal communication issues, and restricted behaviors. Nutritional issues, such as food allergies and intolerances, can affect children with ASD. This study aimed to evaluate the impact of diet programs on ASD behavior and gastrointestinal symptoms, which would be considered as a starting point to increase the family's knowledge about how to practice healthy and suitable dieting for their children. The study was a cross-sectional observational study on 45 children with an autism spectrum disorder in four centers aged 2-18 in Khartoum state. Data was collected through an interview questionnaire, which included sociodemographic, diet, gastrointestinal, and behavioral assessments. The data was analyzed using SPSS to find the correlation between the various variables. Independent t-test, Analysis of Variance, and Mann-Whitney test were used in univariant analysis to assess the association between study variables, while multiple linear regression was used in multivariant analysis for the same purpose. The study involved a large number of children with autism spectrum disorder (ASD), with 80% being male and 73.3% being school-aged. Most had parents as guardians and 71.1% were in intermediate financial status. About 20% were overweight or obese, and 57.8% did not have a specific diet program. Food selectivity was prevalent, with 22.7% having allergies to milk and wheat. ASD children experienced vomiting, gastric reflux, abdominal pain, and changes in stool characteristics. A significant link was found between financial status, behavioral status and gastrointestinal changes. High financial status was significantly different from intermediate and low statuses based on behavioral changes. However, no significant association was found in multivariant analysis. The study found that ASD children generally have good nutritional health, with a higher degree of dietary selection. The financial status of guardians significantly influenced behavioral and gastrointestinal changes in the children. Further interventional studies are recommended to assess the direct impact of diet programs on these symptoms.

Dietary Niche Variation in an Invasive Omnivore: The Effects of Habitat on Feral Pig Resource Use in Hawai'i.

Invasive omnivores may have profound impacts on ecological communities through diet selection, particularly when their functional roles differ from those in their native range. While the threat of feral pigs (Sus scrofa) to native plant communities in Hawai'i is well known, their trophic dynamics and the drivers of variation in their diet remain understudied. We investigated the feral pig trophic niche on Hawai'i Island using stable isotopes (13C and 15N) and Bayesian mixing models to identify drivers of variation in resource use. We also reconstructed intra-individual variability for six subsampled individuals to understand temporal variation in resource use and individual diet specialization. Our results revealed that feral pigs on Hawai'i Island exhibit a broad trophic niche characterized by diverse diets, with substantial overlap in resource use across districts and habitats. Differences in dietary composition in the transition from forest to open habitat were driven primarily by a decline in invertebrates and an increasing reliance on resources enriched in 15N, which may reflect a shift in protein sources with habitat. Pigs in forested areas exhibited a smaller trophic niche than those in open habitats, largely driven by differences in feeding strategies and resource availability. Diets for subsampled individuals varied little, suggesting feral pig resource-use strategies in Hawai'i tend to be relatively stable through time. Individual niche width was relatively narrow compared to that of feral pigs in Hawai'i at large, indicating the relatively wide feral pig dietary niche is characterized by substantial intraspecific diet specialization, likely as a result of strong intraspecific competition. Understanding the drivers of feral pig resource use offers key information for management strategies aimed at mitigating their ecological impacts in imperiled systems like Hawai'i.

Detrimental Effects of Diet Selection in Hospitalized Patients with ESKD

Detrimental Effects of Diet Selection in Hospitalized Patients with ESKD

Study on Rumen Degradability and Intestinal Digestibility of Mutton Sheep Diets with Different Concentrate-to-Forage Ratios and Nonfiber Carbohydrates/Neutral Detergent Fiber Ratios.

This study was conducted to investigate the rumen degradability and intestinal digestibility of mutton sheep diets different in concentrate-to-forage ratio, NFC/NDF, and ingredient combination, providing a guideline for the selection of a fattening diet for mutton sheep. Twenty-eight diets composed of four raw material combinations and seven concentrate-to-forage ratios and four three-year-old mutton sheep with permanent rumen fistulas were used in the experiments. The nutrient composition of the diets was first analyzed, and then an in situ method and in vitro three-step method were separately used to measure the rumen degradability and intestinal digestibility, mainly focusing on the effects of dietary concentrate-to-forage ratio and NFC/NDF as well as the effects of soybean meal and soybean meal replacement and peanut vine and peanut vine replacement. The results showed that a dietary concentrate-to-forage ratio of 70:30~80:20 and an NFC/NDF ratio of 1.5~2.0 are recommended for fattening mutton sheep, and low-cost cottonseed meal and rapeseed meal can be feasible alternative protein sources to soybean meal. In addition, the nutritional values of sunflower seed hulls and rice hulls for mutton sheep are lower than that of peanut vine. Such a study can provide practical guidelines for enterprises and farmers, being of important significance for the high-quality development of the mutton sheep industry.

Changes in the Fatty Acid Composition of Vegetable Oils Affect the Feeding Behavior, Feed Preference, and Thermoregulatory Responses of Sheep

This research evaluated the effects of energy supplementation on sheep’s feeding behavior, feed preference, and thermoregulatory responses using technical cashew nutshell liquid (CNSL) and different vegetable oils with different unsaturated fatty acid (UFA) compositions. The experiment was completely randomized with five treatments: a mixture of CNSL (0.5%) + vegetable oils [canola (high in monounsaturated fatty acids—MUFA), and corn, soybean, sunflower, or cottonseed oil (high in polyunsaturated fatty acids-PUFA) at 1.5%] based on total diet dry matter, with eight replications. Forty uncastrated male sheep, with an average initial BW of 24.44 ± 1.5 kg, were evaluated for 70 days. The CNSL + vegetable oil blend did not affect DM and neutral detergent fiber (aNDF) intake (p &gt; 0.05). However, diets with canola oil resulted in higher SFA intake (p &lt; 0.05) than other oils. The canola oil + CNSL blend led to a higher intake of UFA and MUFA and lower PUFA intake than other oil blends (p &lt; 0.05). Sheep fed canola oil ruminated fewer boli per day than those fed soybean and sunflower oils. Using three sieves (pef1.18) reflected in higher sheep aNDF intake. Respiratory frequency and surface temperature of sheep were lower before feeding than 3 h after, without effects of the type of oil. Higher serum creatinine and cholesterol levels were observed in sheep fed CNSL with corn and canola oils compared to other oils. Serum calcium was lower in sheep fed CNSL with soybean and canola compared to sunflower and corn. Including CNSL with vegetable oils with different FA compositions did not affect physiological and thermographic variables. However, sheep showed better diet selectivity and lower bolus rumination with higher MUFA (canola oil) content. Including CNSL with canola oil in sheep diets is recommended, as it increases dietary energy content, enhances diet selectivity, reduces PUFA intake, and does not impact animal health.

Current Awareness and Knowledge of Heavy Metals

This review discusses public health hazards associated with environmental heavy metals, focusing on those that are especially toxic and persistent: lead, mercury, cadmium, arsenic, chromium, copper, nickel, and zinc. Most of the discussion in this review is devoted to identifying potential routes of exposure and the potential health effects that these metals might pose. In addition, the effectiveness of educational programs is considered, together with demographic factors influencing public knowledge. The methodology includes a detailed literature review to highlight gaps in knowledge and the impacts of the education process. The preliminary findings show very limited knowledge among the public about the risks from toxic metals, especially among children and people working in the industrial sectors. Notwithstanding the aforementioned educational initiatives, there is still a greater need for further intervention strategies to increase awareness and ensure safety. Further, the review shows a lack of concerted efforts on strategies aimed at reducing heavy metal toxicity, including chelation therapy, phytoremediation, and advanced techniques like electro sorption and nanotechnology. The text further examines the efficacy of dietary selections and supplements as natural detoxification techniques that could assist the body in expelling these harmful substances. The study thus concludes emphatically that mitigating the risks of exposure to heavy metals requires increasing public awareness and education, imposing strict regulations on emissions from industries, and involving the community. Policymakers, educators, and health professionals must be unified on a single platform to spread awareness about effective remediation and natural detoxification methodologies. Heavy metals largely threaten human health and ecosystems, so the protection of human health and the maintenance of ecosystems require a comprehensive approach.

What does it take to revolutionize Chinese diets: evidence from a choice experiment on urban Chinese consumers

PurposeThe purpose is to understand the factors affecting Chinese diet selections and propose strategies for revolutionizing Chinese diets toward healthy ones.Design/methodology/approachThis study implemented an online discrete choice experiment to identify the factors affecting diet selections among urban Chinese consumers. Four different diet patterns were used to label each of the product alternatives in the experiment, which varied in taste and cost. Specifically, implying the healthiness and sustainability of a diet, the diet alternatives included the average diet, the Chinese Food Guide Pagoda diet, the EAT-Lancet diet and the Flexitarian diet. Using consumer data from six provincial capital cities, we used random parameter logit models to estimate their preferences.FindingsDiet type and diet cost were found to be more important in urban Chinese consumers' diet selections than the ability to customize taste. The average diet, although not healthy and sustainable, was preferred most by respondents, signaling the challenges of shifting the consumer diet in China. Increasing the cost of the average diet can significantly promote sustainable healthy diet choices among urban Chinese residents. In other words, improving the affordability of sustainable healthy diets would have the potential to fuel the diet revolution in China.Originality/valueInstead of choices of a single food item, this paper focused on the individual selection of a diet, where different food products can act as substitutes or as complements for one another. We also proposed a way to assess individual preferences and valuations for several different diets.

Integrating eDNA metabarcoding and citizen science enhances avian ecological research.

Research Highlight: Bourbour etal., 2024. Feeding en route: Prey availability and traits influence prey selection by an avian predator on migration. Journal of Animal Ecology. Diet selection plays a key role in the eco-evolutionary dynamics of animals, exhibiting substantial variability across species, environments and seasons. The complex interplay between movement capability, hunting strategies, habitat use, prey traits and availability shapes the foraging patterns of avian predators. However, detailed information on how these birds exploit their extensive territories remains limited. In this study, Bourbour etal. utilised a novel integration of eDNA metabarcoding and citizen science to explore predator-prey interactions between migrating sharp-shinned hawks (Accipiter striatus) and an ephemeral avian prey community along North America's Pacific flyway. The research identified 1396 detections from the diet (65 species) of 588 migrating sharp-shinned hawks. Hawks' diet composition correlated with prey abundance indices sourced from the eBird database throughout the migration season, highlighting the significant impact of prey availability-shaped by migration tendency, flocking behaviour, and habitat-on raptor-songbird interactions. Notably, the study also found significant differences in prey size between male and female hawks, indicating that sexual dimorphism has led to diverse foraging strategies during migration. These findings underscore the potential of combining eDNA metabarcoding with citizen science to deepen our understanding of the foraging ecology of highly mobile and wide-ranging birds, as well as to monitor complex and vast ecosystems.

Influence of diet on the course and activity of Crohn's disease and ulcerative colitis - a review of available literature

Introduction: Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the digestive tract. It is a clinical entity that includes: Crohn's disease (CD) and ulcerative colitis (UC). Food intake is an important environmental factor that influences the development of IBD. This article reviews studies on different dietary options and their effects on the course and activity of Crohn's disease and ulcerative colitis. Materials and methods: A review of the literature available in the PubMed database was carried out, using the key words: ”inflammatory bowel disease”; ”Crohn disease”; ”diet”; “nutrition”; „colitis ulcerosa”. Results: Appropriate diet selection is important in the course of inflammation in the intestines. It influences disease activity. It turns out that the diet improves inflammation parameters, clinical symptoms, and quality of life. In patients with inflammatory bowel disease, one should also remember about deficiencies such as iron, vitamin D or protein deficiency, the demand of which is increased in sick patients compared to the general population. Conclusions: An individualized approach to nutritional therapy may be one of the main branches of treatment for patients with inflammatory bowel diseases. However, there is a need for further research on larger groups of patients in order to effectively implement it into treatment standards.

Dietary flexibility of insectivorous bats, Eptesicus fuscus and Myotis lucifugus, during Magicicada spp. Brood X emergence

Emergence of periodical cicadas, Magicicada spp. Davis, 1925, presents an ideal opportunity to study dietary flexibility and selective feeding behavior of bats. It is known that a wide array of taxa prey upon Magicicada spp., but few bat species have been documented to consume them. When larger than typical prey items, such as periodical cicadas, become abundant for a short time frame, insectivorous bats may exhibit alteration in dietary selection that provides insight into capacity and conditions for feeding. Evidence of Magicicada spp. consumption was detected in guano via polymerase chain reaction (PCR) and physical detection in both Eptesicus fuscus (Palisot de Beauvois, 1796) and Myotis lucifugus (Le Conte, 1831), two bat species of different sizes and with different dietary profiles. The consumption of these larger prey items, when they are locally abundant, supports a display of opportunistic behavior and diet flexibility in these two bat species.

Conducting a successful diet trial for the diagnosis of food allergy in dogs and cats.

A limited antigen diet trial and subsequent food provocation is currently the optimal method of confirming a diagnosis of food allergy in dogs and cats. However, performing an effective diet trial can be challenging as it requires a high level of client and pet compliance, appropriate diet selection and correct interpretation of the provocative challenge. This narrative guides the clinician through the process, highlights potential pitfalls and specifies how these can be avoided to achieve a successful outcome.

Larval coregonine density and diet composition along beaches of northern Lake Michigan

Recent oligotrophication in Lake Michigan has contributed to reduced biomass of spring zooplankton and a shift in the zooplankton assemblage toward more calanoid copepods. These changes have likely altered prey availability for first feeding native fish species that hatch in early spring. While spring zooplankton densities and assemblage compositions are routinely monitored in offshore areas of Lake Michigan, zooplankton in nearshore areas such as shallow beach environments are less studied; and associated descriptions of diet characteristics among larval coregonine species are limited. In this study, we a) describe the nearshore (<1 m depth) zooplankton assemblage at four sites in northeastern Lake Michigan during early spring 2015–2019 and b) compare diets and diet selectivity of larval lake whitefish (Coregonus clupeaformis) and Cisco (C. artedi). Zooplankton composition varied among years, but calanoid copepods and copepod nauplii consistently dominated the zooplankton assemblage. Cisco and lake whitefish larvae were captured regularly, with Elk Rapids containing the highest proportion of ciscoes each year. For both species, calanoid and cyclopoid copepods were common in diets and were positively selected as prey. Although previous research has indicated high consumption of cyclopoid copepods by larval coregonines, our results provide new evidence that larval lake whitefish and Cisco in northeastern Lake Michigan will also consume and select for calanoid copepods when they are abundant. As such, should calanoid zooplankton continue to dominate the copepod community in Lake Michigan, larval coregonines appear capable of exploiting this abundant prey resource to improve their likelihood of survival to later life stages.

Association of maternal genetics with the gut microbiome and eucalypt diet selection in captive koalas.

Koalas, an Australian arboreal marsupial, depend on eucalypt tree leaves for their diet. They selectively consume only a few of the hundreds of available eucalypt species. Since the koala gut microbiome is essential for the digestion and detoxification of eucalypts, their individual differences in the gut microbiome may lead to variations in their eucalypt selection and eucalypt metabolic capacity. However, research focusing on the relationship between the gut microbiome and differences in food preferences is very limited. We aimed to determine whether individual and regional differences exist in the gut microbiome of koalas as well as the mechanism by which these differences influence eucalypt selection. Foraging data were collected from six koalas and a total of 62 feces were collected from 15 koalas of two zoos in Japan. The mitochondrial phylogenetic analysis was conducted to estimate the mitochondrial maternal origin of each koala. In addition, the 16S-based gut microbiome of 15 koalas was analyzed to determine the composition and diversity of each koala's gut microbiome. We used these data to investigate the relationship among mitochondrial maternal origin, gut microbiome and eucalypt diet selection. This research revealed that diversity and composition of the gut microbiome and that eucalypt diet selection of koalas differs among regions. We also revealed that the gut microbiome alpha diversity was correlated with foraging diversity in koalas. These individual and regional differences would result from vertical (maternal) transmission of the gut microbiome and represent an intraspecific variation in koala foraging strategies. Further, we demonstrated that certain gut bacteria were strongly correlated with both mitochondrial maternal origin and eucalypt foraging patterns. Bacteria found to be associated with mitochondrial maternal origin included bacteria involved in fiber digestion and degradation of secondary metabolites, such as the families Rikenellaceae and Synergistaceae. These bacteria may cause differences in metabolic capacity between individual and regional koalas and influence their eucalypt selection. We showed that the characteristics (composition and diversity) of the gut microbiome and eucalypt diet selection of koalas differ by individuals and regional origins as we expected. In addition, some gut bacteria that could influence eucalypt foraging of koalas showed the relationships with both mitochondrial maternal origin and eucalypt foraging pattern. These differences in the gut microbiome between regional origins may make a difference in eucalypt selection. Given the importance of the gut microbiome to koalas foraging on eucalypts and their strong symbiotic relationship, future studies should focus on the symbiotic relationship and coevolution between koalas and the gut microbiome to understand individual and regional differences in eucalypt diet selection by koalas.