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Reinventing the wheel : milk, microbes, and the fight for real cheese
\"Reinventing the Wheel is equal parts popular science, history, and muckraking. Over the past hundred and fifty years, dairy farming and cheesemaking have been transformed, and this book explores what has been lost along the way. Today, using cutting-edge technologies like high-throughput DNA sequencing, scientists are beginning to understand the techniques of our great-grandparents. The authors describe how geneticists are helping conservationists rescue rare dairy cow breeds on the brink of extinction, microbiologists are teaching cheesemakers to nurture the naturally occurring microbes in their raw milk rather than destroying them, and communities of cheesemakers are producing \"real\" cheeses that reunite farming and flavor, rewarding diversity and sustainability at every level.\"--Provided by publisher.
Book
Effects of Heat-Treated Lactobacillus helveticus CP790-Fermented Milk on Gastrointestinal Health in Healthy Adults: A Randomized Double-Blind Placebo-Controlled Trial
Probiotic-fermented milk is commonly used to maintain intestinal health. However, the effects of heat-treated fermented milk, which does not contain live microorganisms, on intestinal function are not yet fully understood. This study aimed to investigate whether heat-treated Lactobacillus helveticus CP790-fermented milk affects fecal microbiota and gut health as a “postbiotic”. A randomized, double-blind, placebo-controlled trial was conducted in healthy Japanese individuals aged 20–59 years with a tendency toward constipation. Participants consumed 100 mL of either the test beverage (n = 60) or placebo beverage (n = 60) for four weeks. The test beverages were prepared with heat-treated CP790-fermented milk, while the placebo beverages were prepared with nonfermented milk flavored with lactic acid. Fecal samples were analyzed using 16S rRNA gene sequencing. Constipation symptoms were assessed using defecation logs and the Patient Assessment of Constipation Symptoms (PAC-SYM) questionnaire. Mood state was also assessed using the Profile of Mood States 2 (POMS2) questionnaire to explore its potential as a “psychobiotic”. Desulfobacterota were significantly decreased by CP790-fermented milk intake. PICRUSt2 analysis predicted a decrease in the proportion of genes involved in the sulfate reduction pathway following the consumption of CP790-fermented milk. The CP790-fermented milk intervention significantly improved stool consistency and straining during defecation. These improvements were correlated with a decrease in Desulfobacterota. After the intervention, overall mood, expressed as total mood disturbance, and depression–dejection were significantly better in the CP790 group than in the placebo group. These results suggest that the intake of CP790-fermented milk could be effective in modulating gut microbiota and improving constipation symptoms and mood states.
Journal Article
Preventive Effect of Cow’s Milk Fermented with Lactobacillus paracasei CBA L74 on Common Infectious Diseases in Children: A Multicenter Randomized Controlled Trial
Background: Fermented foods have been proposed to prevent common infectious diseases (CIDs) in children attending day care or preschool. Objectives: To investigate the efficacy of dietary supplementation with cow’s skim milk fermented with the probiotic Lactobacillus paracasei CBA L74 in reducing CIDs in children attending day care or preschool. Methods: Multicenter, randomized, double-blind, placebo-controlled trial on healthy children (aged 12–48 months) consuming daily 7 grams of cow’s skim milk fermented with L. paracasei CBA L74 (group A), or placebo (maltodextrins group B) attending day care or preschool during the winter season. The main outcome was the proportion of children who experienced ≥1 episode of CID during a 3-month follow-up. Fecal biomarkers of innate (α- and β-defensins, cathelicidin) and acquired immunity (secretory IgA) were also monitored. Results: A total of 126 children (71 males, 56%) with a mean (SD) age of 33 (9) months completed the study, 66 in group A and 60 in group B. At intention to treat analysis, the proportion of children presenting ≥1 CID was 60% in group A vs. 83% in group B, corresponding to an absolute risk difference (ARD) of −23% (95% CI: −37% to −9%, p < 0.01). At per-protocol-analysis (PPA), the proportion of children presenting ≥1 CID was 18% in group A vs. 40% in group B, corresponding to an absolute risk difference (ARD) of −22% (95% CI: −37% to −6%, p < 0.01). PPA showed that the proportion of children presenting ≥1 acute gastroenteritis (AGE) was significantly lower in group A (18% vs. 40%, p < 0.05). The ARD for the occurrence of ≥1 AGE was −22% (95% CI: −37% to −6%, p < 0.01) in group A. Similar findings were obtained at PPA regarding the proportion of children presenting ≥1 upper respiratory tract infection (URTI), which was significantly lower in group A (51% vs. 74%, p < 0.05), corresponding to an ARD of −23% (95% CI: −40% to −7%, p < 0.01). Significant changes in innate and acquired immunity biomarkers were observed only in subjects in group A. Conclusions: Dietary supplementation with cow’s skim milk fermented with L. paracasei CBA L74 is an efficient strategy in preventing CIDs in children.
Journal Article
Probiotic reduces bacterial translocation in type 2 diabetes mellitus: A randomised controlled study
Gut bacterial translocation to the blood may play an important role in the development of insulin resistance in type 2 diabetes. Here, we performed an interventional randomised control study to investigate whether probiotics could reduce bacterial translocation and cause changes in the gut microbiota. Seventy Japanese patients with type 2 diabetes were randomised to two groups: the probiotic group drank
Lactobacillus casei
strain Shirota-fermented milk, while the control group ingested no probiotics. The trial was conducted for 16 weeks. At baseline, 8 and 16 weeks, the gut microbiota composition in feces and blood, fecal organic acids, and other biochemical parameters were measured. At the end of the study, the fecal counts of the
Clostridium coccoides
group and
Clostridium leptum
subgroup in the probiotic group were significantly higher than in the control group. As expected, the fecal counts of total
Lactobacillus
were significantly higher in the probiotic group. Intriguingly, the total count of blood bacteria was significantly lower in the probiotic group. However, fecal organic acids were comparable between the two groups. Our results showed that probiotic administration reduced bacterial translocation and altered the gut microbiota in Japanese patients with type 2 diabetes mellitus.
Journal Article
The effects of Thymus capitatus essential oil topical application on milk quality: a systems biology approach
Essential oils (EO) are known for their antibacterial and anti-inflammatory properties and can be used as an alternative to reduce the reliance on antimicrobials in dairy cattle. While many studies have explored the beneficial properties of EO in vitro, their effects on milk quality and milk microbiota, when applied directly to the udder skin, remain relatively unknown. This study aimed to investigate the impact of Thymus capitatus essential oil (TCEO), known for its high antibacterial and antioxidant properties, on milk microbiota using 16S rRNA sequencing, the lipidomic profile via liquid chromatography-quadrupole time-of-flight mass spectrometry, udder skin microbiota, and inflammatory biomarkers of dairy cows at the end of lactation. Sixteen-quarters of 12 Holstein cows were selected, and TCEO was topically applied to the udder skin twice a day for 7 days. Milk was collected aseptically on days 0, 7, 21, and 28 before morning farm milking. The results showed no significant changes in microbiota composition after the EO treatment in alpha and beta diversity or taxonomical composition at the phylum and genus levels. TCEO induced limited changes in the milk lipidome, primarily affecting diacylglycerols at T21. The treatment did not affect inflammatory biomarkers, milk sensory properties, or quality. Our study is the first to demonstrate that a local application of 10% TCEO on cow’s quarters does not significantly alter milk quality or microbiota composition in milk and skin. More studies should be conducted to ensure the safe use of TCEO in dairy cows and explore its potential benefits on antibiotic-resistant bacteria as an alternative or support for antibiotic therapy.
Journal Article
Effectiveness of zinc supplementation on diarrhea and average daily gain in pre-weaned dairy calves: A double-blind, block-randomized, placebo-controlled clinical trial
The objective of this clinical trial was to evaluate the effectiveness of zinc supplementation on diarrhea and average daily weight gain (ADG) in pre-weaned dairy calves. A total of 1,482 healthy Holstein heifer and bull calves from a large California dairy were enrolled at 24 to 48 hours of age until hutch exit at approximately 90 days of age. Calves were block-randomized by time to one of three treatments: 1) placebo, 2) zinc methionine (ZM), or 3) zinc sulfate (ZS) administered in milk once daily for 14 days. Serum total protein at enrollment and body weight at birth, treatment end, and hutch exit were measured. Fecal consistency was assessed daily for 28 days post-enrollment. For a random sample of 127 calves, serum zinc concentrations before and after treatment and a fecal antigen ELISA at diarrhea start and resolution for Escherichia coli K99, rotavirus, coronavirus, and Cryptosporidium parvum were performed. Linear regression showed that ZM-treated bull calves had 22 g increased ADG compared to placebo-treated bulls (P = 0.042). ZM-treated heifers had 9 g decreased ADG compared to placebo-treated heifers (P = 0.037), after adjusting for average birth weight. Sex-stratified models showed that high birth weight heifers treated with ZM gained more than placebo-treated heifers of the same birth weight, which suggests a dose-response effect rather than a true sex-specific effect of ZM on ADG. Cox regression showed that ZM and ZS-treated calves had a 14.7% (P = 0.015) and 13.9% (P = 0.022) reduced hazard of diarrhea, respectively, compared to placebo-treated calves. Calves supplemented for at least the first five days of diarrhea with ZM and ZS had a 21.4% (P = 0.027) and 13.0% (P = 0.040) increased hazard of cure from diarrhea, respectively, compared to placebo-treated calves. Logistic regression showed that the odds of microbiological cure at diarrhea resolution for rotavirus, C. parvum, or any single fecal pathogen was not different between treatment groups. Zinc supplementation delayed diarrhea and expedited diarrhea recovery in pre-weaned calves. Additionally, zinc improved weight gain differentially in bulls compared to heifers, indicating a research need for sex-specific dosing.
Journal Article
Comparison of gut microbiota in exclusively breast-fed and formula-fed babies: a study of 91 term infants
To compare gut microbiota of healthy infants that were exclusively breast-fed or formula-fed, we recruited 91 infants, who were assigned into three different groups and fed by breast milk (30 babies), formula A (30 babies) or formula B (31 babies) exclusively for more than 4 months after birth. Faecal bacterial composition was tested. Among different groups, α diversity was lower in breast-fed group than formula-fed groups in 40 days of age, but increased significantly in 6 months of age. The
Bifidobacterium
represented the most predominant genus and
Enterobacteriaceae
the second in all groups. In 40 days of age,
Bifidobacterium
and
Bacteroides
were significantly higher, while
Streptococcus
and
Enterococcus
were significantly lower in breast-fed group than they were in formula A-fed group.
Lachnospiraceae
was lower in breast-fed than formula B-fed group.
Veillonella
and
Clostridioides
were lower in breast-fed than formula-fed groups. In 3 months of age there were less
Lachnospiraceae
and
Clostridioides
in breast-fed group than formula-fed groups. There were also significant differences of microbiota between formula A-fed and formula B-fed groups. Those differences may have impacts on their long-term health.
Journal Article
Temperature abuse and Salmonella Typhimurium colonization disrupt the indigenous bacterial communities of pasteurized bovine milk over time
Even though the population structure of the bovine milk residential bacterial population is known, the alterations in the population structure associated with food safety issues, such as temperature abuse/pathogen colonization, are unknown. Here, alterations of the bacterial population, either incubated at 37 °C (temperature abuse) or inoculated with
Salmonella
Typhimurium (pathogen colonization), were characterized using full-length 16S rRNA sequencing. At zero hour, the bacterial population of milk primarily constituted of Firmicutes and Thermi. Of the 218 genera identified,
Thermus
(37%) and
Streptococcus
(34%) were the most dominant. The 12-h incubation at 37 °C replaced almost 96% of the population by Firmicutes, exemplified by a remarkable increase in the abundance of the genus
Bacillus
. Concurrently, only 36 genera survived, with an abundance of
Bacillus,
which showed a 98-fold increase during the 12-h incubation. Similarly, only 150 genera remained after 12 h in
Salmonella-
inoculated milk. Both temperature abuse and
Salmonella
inoculation significantly reduce bacterial diversity and richness. Nonmetric multidimensional scaling analysis between the control and
Salmonella
inoculated samples was significantly distinct at all times, confirming alterations in the bacterial population during
Salmonella
colonization. Even though the load of Firmicutes increased temporally, bacteria belonging to the genera
Bacillus, Macrococcus,
and
Serratia
genera were depleted in
Salmonella
inoculated milk samples. Taken together, both experimental conditions, viz. temperature abuse and
Salmonella
contamination, demonstrated a significant drop in residential milk bacterial diversity. This general drop in bacterial diversity could allow
Salmonella
to occupy and colonize the milk matrix.
Journal Article
Organic vs. Conventional Milk: Uncovering the Link to Antibiotic Resistance in Bacillus cereus sensu lato
Bacillus cereus sensu lato (B. cereus s.l.) comprises mesophilic and psychrotolerant bacteria commonly found in natural environments as well as in organic and conventional milk. Due to their potential toxigenicity and antibiotic resistance, these bacteria pose a significant threat to consumer health. Organic milk production, which prohibits the use of antibiotics and artificial additives, may influence the composition of microbiota between milk types. This study aimed to compare the antibiotic resistance profiles and enterotoxic potential of B. cereus s.l. isolates from organic and conventional milk. The results indicate that, although conventional milk contains on average 3 times fewer B. cereus s.l. isolates, it has 10–15% more resistant isolates to selected beta-lactams, macrolides, and aminoglycosides. Regarding drug resistance, 21% of B. cereus s.l. isolates were multidrug-resistant, and as many as 42% were non-susceptible to two classes of antibiotics. Even among the sensitive isolates, bacteria from conventional milk exhibited on average 2.05 times higher MICs (minimal inhibitory concentrations) for beta-lactams, 1.49 times higher for erythromycin, 1.38 times higher for vancomycin, and 1.38 times higher for azithromycin. Antibiotic resistance was mostly associated with the origin of the isolates. These findings underscore the need for ongoing monitoring of antibiotic resistance and enterotoxicity among opportunistic B. cereus s.l. strains, which may pose challenges for public health and veterinary medicine. The results highlight that selective pressure associated with antibiotic use can drive resistance development in bacteria that are not the primary targets of antimicrobial therapy.
Journal Article
Sequencing-Based Analysis of the Bacterial and Fungal Composition of Kefir Grains and Milks from Multiple Sources
Kefir is a fermented milk-based beverage to which a number of health-promoting properties have been attributed. The microbes responsible for the fermentation of milk to produce kefir consist of a complex association of bacteria and yeasts, bound within a polysaccharide matrix, known as the kefir grain. The consistency of this microbial population, and that present in the resultant beverage, has been the subject of a number of previous, almost exclusively culture-based, studies which have indicated differences depending on geographical location and culture conditions. However, culture-based identification studies are limited by virtue of only detecting species with the ability to grow on the specific medium used and thus culture-independent, molecular-based techniques offer the potential for a more comprehensive analysis of such communities. Here we describe a detailed investigation of the microbial population, both bacterial and fungal, of kefir, using high-throughput sequencing to analyse 25 kefir milks and associated grains sourced from 8 geographically distinct regions. This is the first occasion that this technology has been employed to investigate the fungal component of these populations or to reveal the microbial composition of such an extensive number of kefir grains or milks. As a result several genera and species not previously identified in kefir were revealed. Our analysis shows that the bacterial populations in kefir are dominated by 2 phyla, the Firmicutes and the Proteobacteria. It was also established that the fungal populations of kefir were dominated by the genera Kazachstania, Kluyveromyces and Naumovozyma, but that a variable sub-dominant population also exists.
Journal Article