Search Results (27)

The aim of this study was to understand the status of Mycobacterium paratuberculosis infection in a large-scale dairy farm in Xi’an city and evaluate the impact via a “quarantine + elimination” model of bovine paratuberculosis on the production performance, reproductive performance, and economic benefits in said dairy farm. The paratuberculosis antibodies from 4488 dairy cow sera were detected by an ELISA kit, complemented by a comprehensive analysis of milk production parameters, health metrics, reproductive indices, and pharmaceutical expenditures (2021–2024). The results indicated that the paratuberculosis prevalence in the dairy farm gradually reduced from 6.76% (2021) to 3.58% (2024). It was also found that the paratuberculosis prevalence among dairy cows increased progressively with the increase in parity until the fifth calving, after which a significant decline was observed. The reduction in infection rates in the herd was correlated with measurable improvements in milk quality metrics, including elevated milk fat and protein content, extended shelf stability, and decreased somatic cell counts in milk. In addition, the reproductive performance of the dairy cows relatively improved with the decrease in paratuberculosis prevalence; there was a relative improvement in the reproductive performance of the dairy cows, which mainly occurred by the time of pregnancy at the first service of the cows, while the number of monthly occurrences of endometritis, diarrhea, calving intervals, and inseminations decreased. Further data correlation analysis showed that daily milk volume was positively correlated with lactase persistence (95% CI: 0.247–0.753, p = 0.001) and peaked at the day of milk production (95% CI: 0.135–0.698, p = 0.008) but was negatively correlated with parity (95% CI: −0.783–−0.315). In addition, lactation time was positively correlated with 305-day milk volume (95% CI: 0.173–0.718, p < 0.004) and peaked at the day of milk production (95% CI: 0.265–0.761) but showed the opposite trend with the milk fat rate (95% CI: −0.633–−0.018, p = 0.040) and milk protein rate (95% CI: −0.738–−0.215, p = 0.002). Furthermore, milk loss was negatively correlated with peak milk production (95% CI: −0.758–−0.258, p = 0.001). Intriguingly, the cost of medications for diarrhea exhibited a downward trend over the past three years. Taken together, these findings confirmed the necessity to reduce the incidence of Mycobacterium avium subsp. paratuberculosis in dairy cows and serve as a guide for the future successful and gradual eradication of paratuberculosis in Chinese dairy cow farms. Full article

Background: In prehistoric societies, especially in the Neolithic period, the study of the palaeodiet assumes special importance as it is one of the points in human history characterised by important changes in diet. In this context, the study of food intolerances is even more significant. Methods: Some of the individuals studied were analysed from a genetic point of view, while a systematic literature review was performed from a genetic perspective, verifying the persistence or absence of lactase in adulthood, and information from necropolises regarding the presence of biomarkers linked to possible consumption of dairy products was analysed. Results: The results indicate a clear majority of individuals with hypolactasia in adulthood, although in a Pyrenean necropolis, studied here for the first time, the lactase persistence allele was already detected. Dairy consumption was also verified to be widespread in very early Neolithic periods. Conclusions: From a population perspective, this study enables a deeper understanding of past populations’ daily lives, expanding our perspective on their dietary patterns. From an evolutionary standpoint, it illuminates a pivotal point in human history and evolution within the European context, where past and modern dairy consumption, particularly cheese, has profound implications for both present and past economies. Full article

The rise in food intolerances and celiac disease, along with advanced diagnostic techniques, has prompted health professionals to seek effective and economical testing methods. This study evaluates combining genetic tests with routine carbohydrate-absorption breath tests to classify patients with chronic gastrointestinal disorders into therapeutic groups, enhancing dietary management and improving gut health and quality of life. Forty-nine patients with suspected carbohydrate intolerance underwent genetic testing for lactase non-persistence, hereditary fructose intolerance, and celiac disease risk. Simultaneously, breath tests assessed lactose and fructose absorption. The lactase non-persistence genotype appeared in 36.7% of cases, with one hereditary fructose-intolerance case in a heterozygous condition. Celiac disease risk markers (HLA-DQ2/8 haplotypes) were found in 49.0% of the population. Secondary lactose and/or fructose malabsorption was present in 67.3% of patients, with 66.1% of lactase non-persistence individuals showing secondary lactose malabsorption. Fructose malabsorption was prevalent in 45.8% of patients at risk for celiac disease. Two main treatment groups were defined based on genetic results, indicating primary and irreversible gastrointestinal disorder causes, followed by a sub-classification using breath test results. Genetic testing is a valuable tool for designing dietary management plans, avoiding unnecessary diet restrictions, and reducing recovery times. Full article

Lactose intolerance, which affects about 65–75% of the world’s population, is caused by a genetic post-weaning deficiency of lactase, the enzyme required to digest the milk sugar lactose, called lactase non-persistence. Symptoms of lactose intolerance include abdominal pain, bloating and diarrhea. Genetic variations, namely lactase persistence, allow some individuals to metabolize lactose effectively post-weaning, a trait thought to be an evolutionary adaptation to dairy consumption. Although lactase non-persistence cannot be altered by diet, prebiotic strategies, including the consumption of galactooligosaccharides (GOSs) and possibly low levels of lactose itself, may shift the microbiome and mitigate symptoms of lactose consumption. This review discusses the etiology of lactose intolerance and the efficacy of prebiotic approaches like GOSs and low-dose lactose in symptom management. Full article

Previous research has found that milk is associated with a decreased risk of colorectal cancer (CRC). However, it is unclear whether the milk digestion by the enzyme lactase-phlorizin hydrolase (LPH) plays a role in CRC susceptibility. Our study aims to investigate the direct causal relationship of CRC risk with LPH levels by applying a two-sample Mendelian Randomization (MR) strategy. Genetic instruments for LPH were derived from the Fenland Study, and CRC-associated summary statistics for these instruments were extracted from the FinnGen Study, PLCO Atlas Project, and Pan-UK Biobank. Primary MR analyses focused on a cis-variant (rs4988235) for LPH levels, with results integrated via meta-analysis. MR analyses using all variants were also undertaken. This analytical approach was further extended to assess CRC subtypes (colon and rectal). Meta-analysis across the three datasets illustrated an inverse association between genetically predicted LPH levels and CRC risk (OR: 0.92 [95% CI, 0.89–0.95]). Subtype analyses revealed associations of elevated LPH levels with reduced risks for both colon (OR: 0.92 [95% CI, 0.89–0.96]) and rectal cancer (OR: 0.92 [95% CI, 0.87, 0.98]). Consistency was observed across varied analytical methods and datasets. Further exploration is warranted to unveil the underlying mechanisms and validate LPH’s potential role in CRC prevention. Full article

Background and objectives: Globally, about 70% of the adult population is lactase non-persistent (LNP), lacking the enzyme required for lactose digestion. The main consequence of intolerance is withholding nutrient-rich dairy foods, while the literature shows that many LNPers are able to consume ≤12 g of lactose, comparable to 250 mL of milk, without experiencing gastrointestinal discomfort. Repetitive consumption of lactose may improve intolerance symptoms even further via colonic adaptation. This study aimed to assess the effects of daily consumption of incremental lactose doses on microbiota composition and function, and intolerance symptoms. Methods: Twenty-five healthy adults of Asian origin (age 22–44 yrs, BMI 19–28 kg/m²), carrying the LNP genotype and avoiding lactose in their habitual diet, were included in this 12-week single-blinded intervention trial. Participants consumed lactose twice daily, with doses being gradually increased from 3 to 6 g, to finally 12 g twice daily, each dose being provided for 4 consecutive weeks. Before and after the 12-week intervention, participants underwent a 25 g lactose challenge hydrogen breath test (HBT) and handed in stool samples. Daily gastrointestinal symptoms and acute intolerance symptoms during the HBT were recorded. Results: There was a significant increase in Bifidobacterium after 12 weeks of lactose consumption (p = 0.009), accompanied by a two-fold increase (p < 0.001) in fecal β-galactosidase activity. There was a 1.5-fold decrease (AUC; p = 0.01) in expired hydrogen during the second compared to the baseline HBT. There was a non-significant decrease in total symptom score (p = 0.09) during this second HBT, which was already relatively low during the baseline HBT. Daily consumption of lactose was generally well tolerated, with mild to no gastrointestinal complaints reported during the intervention. Discussion: Repetitive consumption of incremental doses of lactose increases lactose tolerance in LNP individuals via colonic adaptation, most likely through increasing the relative abundance of lactose-fermenting Bifidobacterium. Repetitive lactose consumption is well tolerated and able to reduce expired hydrogen during a 25 g lactose HBT. Here, we show that regular and incremental exposure to lactose in LNP individuals leads to colonic adaptation without any increase in gastrointestinal symptoms. This lifts the necessity to remove dairy foods completely from the diet. Full article

Intolerance to dairy products resulting from the abnormal digestion of milk sugar (lactose) is a common cause of human gastrointestinal disorders. The aim of this study was to show that the -13910 C>T LCT gene polymorphism, together with genotypes of selected VDR gene polymorphisms and diet and nutritional status parameters, can impact the prevalence of vitamin D and calcium deficiency in young adults. This study was conducted on a group of 63 people, which comprised 21 individuals with primary adult lactase deficiency, and a control group of 42 individuals with no hypolactasia. The LCT and VDR gene genotypes were assessed using PCR restriction fragment length polymorphism (PCR-RFLP) analysis. A validated HPLC method was used to determine serum concentrations of 25(OH)D₂ and 25(OH)D₃. Atomic absorption spectrometry was used to determine calcium levels. Their diets (self-reported 7-day estimated food record), estimated calcium intakes based on the ADOS-Ca questionnaire and basic anthropometric parameters were assessed. The CC genotype associated with hypolactasia was found in 33.3% of the subjects. The presence of the CC variant of the LCT gene polymorphism in the study group of young Polish adults was found to be associated with significantly lower milk (134.7 ± 66.7 g/d vs. 342.5 ± 176 g/d; p = 0.012) and dairy product consumption (78.50 ± 36.2 g/d vs. 216.3 ± 102 g/d; p = 0.008) compared with lactase persistence. At the same time, people with adult-type primary intolerance were found to have statistically significant lower serum levels of vitamin D and calcium (p < 0.05). There was a higher chance of vitamin D and calcium deficiency and a lower intake in the group exhibiting lactase non-persistence (OR > 1). The AA variant of the VDR gene’s BsmI polymorphism present in people with hypolactasia may further contribute to an increased risk of vitamin D deficiency. Exclusion of lactose from the diet, combined with impaired vitamin D metabolism, may also lead to inhibited calcium absorption by the body. Further research should be carried out on a larger group of subjects to clarify the relationship between lactase activity and vitamin D and calcium levels in young adults. Full article

This review focuses on the Sahel/Savannah belt, a large region of Africa where two alternative subsistence systems (pastoralism and agriculture), nowadays, interact. It is a long-standing question whether the pastoralists became isolated here from other populations after cattle began to spread into Africa (~8 thousand years ago, kya) or, rather, began to merge with other populations, such as agropastoralists, after the domestication of sorghum and pearl millet (~5 kya) and with the subsequent spread of agriculture. If we look at lactase persistence, a trait closely associated with pastoral lifestyle, we see that its variants in current pastoralists distinguish them from their farmer neighbours. Most other (mostly neutral) genetic polymorphisms do not, however, indicate such clear differentiation between these groups; they suggest a common origin and/or an extensive gene flow. Genetic affinity and ecological symbiosis between the two subsistence systems can help us better understand the population history of this African region. In this review, we show that genomic datasets of modern Sahel/Savannah belt populations properly collected in local populations can complement the still insufficient archaeological research of this region, especially when dealing with the prehistory of mobile populations with perishable material culture and therefore precarious archaeological visibility. Full article

Background. Lactose malabsorption (LM) is a frequent clinical problem associated with several digestive and extra-digestive diseases. The aim of this manuscript was to clarify the real clinical impact of LM on these disorders. Methods. A literature search for digestive and extra-digestive disorders related to LM was carried out using PubMed, Medline and Cochrane. Results. A transient lactase deficiency is present in celiac disease (CD) on a normal diet. The persistence of symptoms in CD on a gluten-free diet may be instead, in part, attributed to a primary LM. Similar circumstances are present in inflammatory bowel diseases (IBD), in which LM can be responsible for a part of persistent symptoms in IBD on clinical remission. LM and irritable bowel syndrome (IBS) are instead independent conditions. On the other hand, a lactose-restricted diet may be useful for some IBS patients. A reduced lactose intake can lead to low bone mass and limited risk of fragility fractures. Finally, the absorption of levothyroxine could be conditioned by LM. Conclusions. LM can be responsible for persistent symptoms in CD and IBD. The association with IBS seems to be casual. Bone mass and levothyroxine absorption can be affected by LM. Full article

Milk intake has been associated with risk of neurodegenerative diseases in observational studies. Nevertheless, whether the association is causal remains unknown. We adopted Mendelian randomization design to evaluate the potential causal association between milk intake and common neurodegenerative diseases, including multiple sclerosis (MS), Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), and Parkinson’s disease (PD). Genetic associations for neurodegenerative diseases were obtained from the International Multiple Sclerosis Genetics Consortium (n = 80,094), FinnGen consortium (n = 176,899), AD GWAS (n = 63,926), Web-Based Study of Parkinson’s Disease (n = 308,518), PDGene (n = 108,990), and ALS GWAS (n = 80,610). Lactase persistence variant rs4988235 (LCT-13910 C > T) was used as the instrumental variable for milk intake. Genetically predicted higher milk intake was associated with a decreased risk of MS and AD and with an increased risk of PD. For each additional milk intake increasing allele, the odds ratios were 0.94 (95% confidence intervals [CI]: 0.91–0.97; p = 1.51 × 10⁻⁴) for MS, 0.97 (0.94–0.99; p = 0.019) for AD and 1.09 (95%CI: 1.06–1.12, p = 9.30 × 10⁻⁹) for PD. Genetically predicted milk intake was not associated with ALS (odds ratio: 0.97, 95%CI: 0.94–1.01, p = 0.135). Our results suggest that genetically predicted milk intake is associated with a decreased risk of MS and AD but with an increased risk of PD. Further investigations are needed to clarify the underlying mechanisms. Full article

Recent discoveries in the “omics” field and the growing focus on preventive health have opened new avenues for personalized nutrition (PN), which is becoming an important theme in the strategic plans of organizations that are active in healthcare, food, and nutrition research. PN holds great potential for individual health optimization, disease management, public health interventions, and product innovation. However, there are still multiple challenges to overcome before PN can be truly embraced by the public and healthcare stakeholders. The diagnosis and management of lactose intolerance (LI), a common condition with a strong inter-individual component, is explored as an interesting example for the potential role of these technologies and the challenges of PN. From the development of genetic and metabolomic LI diagnostic tests that can be carried out in the home, to advances in the understanding of LI pathology and individualized treatment optimization, PN in LI care has shown substantial progress. However, there are still many research gaps to address, including the understanding of epigenetic regulation of lactase expression and how lactose is metabolized by the gut microbiota, in order to achieve better LI detection and effective therapeutic interventions to reverse the potential health consequences of LI. Full article

(1) Background: Lactose digestion depends on persistence genotypes (including rs4988235), the frequency of which exhibits broad geographical variability. However, little is known about the relationship between lactase (LCT) genotypes and intestinal expression of LCT. We aimed to investigate ileal expression of LCT depending on main genetic polymorphisms (rs4988235, rs3754689, rs3739022), age, sex, smoking status, body mass index (BMI), and the expression of other genes; (2) Methods: phenotype, array-based genotype, and ileal mucosal biopsy expression data were obtained from the CEDAR study; (3) Results: analyses included 196 healthy Europeans (53.6% women) aged 53.0 ± 13.6 years with a mean BMI of 25.6 ± 4.2 kg/m², of whom 17.4% were smoking. Ileal LCT expression was mostly independent of age, sex, BMI, or smoking. Rs4988235 homozygous minor allele (GG) associated with lower LCT expression (vs. AG p = 2.2 × 10⁻⁶, vs. AA p = 1.1 × 10⁻⁷). Homozygous major allele of rs3754689 (GG) was related to higher LCT expression (vs. AG p = 1.7 × 10⁻⁵, vs. AA p = 0.0074). Rs3754689 genotype did not modify LCT expression (GG vs. AG p = 0.051) in rs4988235-heterozygous subgroup. Interestingly, CD14, which is a marker of monocytes and macrophages, was the strongest negative transcriptomic correlate of LCT expression (r = −0.57, p_FDR = 1.1 × 10⁻¹⁴); (4) Conclusions: both rs4988235 and rs3754689 associated with ileal LCT expression, which did not seem related to age, sex, smoking, or BMI. The inverse correlation between LCT and CD14 expression in the ileum is striking and requires further investigation. Full article

Many patients with inflammatory bowel disease (IBD) restrict dairy products to control their symptoms. The aim of the study was to investigate the prevalence of lactose intolerance assessed with hydrogen breath test (H-BT) in IBD patients in clinical remission compared to a sex, age and BMI matched control population. We further detected the prevalence of three single nucleotide polymorphisms of the lactase (LCT) gene: the lactase non persistence LCT-13910 CC (wildtype) and the intermediate phenotype LCT-22018 CT and LCT-13910 AG; finally, we assess the correlation between genotype and H-BT. A total of 54 IBD patients and 69 control who underwent clinical evaluation, H-BT and genetic test were enrolled. H-BT was positive in 64.8% IBD patients and 62.3% control (p = 0.3). The wild-type genotype was found in 85.2% IBD patients while CT-22018, AG-13910 and CT-22018/AG-13910 polymorphisms were found in 9.3%, 1.8% and 3.7%. In the control group, the wild-type genotype, CT-22018, AG-13910 and CT-22018/AG-13910 polymorphisms were found in 87%, 5.8%, 5.8% and 1.4% of cases, respectively. Therefore, the wild-type and polymorphisms’ prevalence did not differ between IBD population and control group (85.2% vs. 87%, p = 0.1) (14.8% vs. 13%, p = 0.7). The correlation between positive H-BT and genetic analysis showed that the wild-type genotype was associated with higher rate of lactose intolerance in the total population (OR 5.31, 95%CI 1.73–16.29, p = 0.003) and in the IBD (OR 7.61, 95%CI 1.36–42.7, p = 0.02). The prevalence of lactose intolerance in IBD patients did not differ from that of control. Despite suggestive symptoms, about 1/3 of IBD patients are not lactose intolerant, thus not needing “a priori” elimination diet. This may encourage a rationale and balanced dietary management in IBD. Full article

Genetic testing is a good predictor of lactase persistence (LP) in specific populations but its clinical utility in children is less clear. We assessed the role of lactose malabsorption in functional gastrointestinal disorders (FGID) in children and the correlation between the lactase non-persistence (LNP) genotype and phenotype, based on exhaled hydrogen and gastrointestinal symptoms, during a hydrogen breath test (HBT). We also evaluate dairy consumption in this sample. We conducted a 10-year cross-sectional study in a cohort of 493 children with suspected FGID defined by Roma IV criteria. Distribution of the C/T-13910 genotype was as follows: CC, 46.0%; TT, 14.4% (LP allele frequency, 34.1%). The phenotype frequencies of lactose malabsorption and intolerance were 36.3% and 41.5%, respectively. We observed a strong correlation between genotype and both lactose malabsorption (Cramér’s V, 0.28) and intolerance (Cramér’s V, 0.54). The frequency of the LNP genotype (p = 0.002) and of malabsorption and intolerance increased with age (p = 0.001 and 0.002, respectively). In 61% of children, evaluated dairy consumption was less than recommended. No association was observed between dairy intake and diagnosis. In conclusion, we found a significant correlation between genotype and phenotype, greater in older children, suggesting that the clinical value of genetic testing increases with age. Full article

In humans the ability to digest milk lactose is conferred by a β-galactosidase enzyme called lactase-phlorizin hydrolase (LPH). While in some humans (approximately two-thirds of humankind) the levels of this enzyme decline drastically after the weaning phase (a trait known as lactase non-persistence (LNP)), some other individuals are capable of maintaining high levels of LPH lifelong (lactase persistence (LP)), thus being able to digest milk during adulthood. Both lactase phenotypes in humans present a complex genetic basis and have been widely investigated during the last decades. The distribution of lactase phenotypes and their associated single nucleotide polymorphisms (SNPs) across human populations has also been extensively studied, though not recently reviewed. All available information has always been presented in the form of static world maps or large dimension tables, so that it would benefit from the newly available visualization tools, such as interactive world maps. Taking all this into consideration, the aims of the present review were: (1) to gather and summarize all available information on LNP and LP genetic mechanisms and evolutionary adaptation theories, and (2) to create online interactive world maps, including all LP phenotype and genotype frequency data reported to date. As a result, we have created two online interactive resources, which constitute an upgrade over previously published static world maps, and allow users a personalized data exploration, while at the same time accessing complete reports by population or ethnicity. Full article