A low-fibre diet leads to gut microbiota imbalance, characterized by low diversity and reduced ability to produce beneficial metabolites, such as short-chain fatty acids (SCFAs). This imbalance is associated with poor gastrointestinal and metabolic health. We aimed to determine whether one dietary change, substitution of white bread with high-fibre bread, improves gut microbiota diversity and SCFA-producing capability. Twenty-two healthy adults completed a two-phase randomized, cross-over trial. The participants consumed three slices of a high-fibre bread (Prebiotic Cape Seed Loaf with BARLEYmax®) or control white bread as part of their usual diet for 2 weeks, with the treatment periods separated by a 4-week washout. High-fibre bread consumption increased total dietary fibre intake to 40 g/d, which was double the amount of fibre consumed at baseline or during the white bread intervention. Compared to white bread, the high-fibre bread intervention resulted in higher faecal alpha diversity (Shannon, p = 0.014) and relative abundance of the Lachnospiracae ND3007 group (p < 0.001, FDR = 0.019) and tended to increase the butyrate-producing capability (p = 0.062). In conclusion, substituting white bread with a high-fibre bread improved the diversity of gut microbiota and specific microbes involved in SCFA production and may enhance the butyrate-producing capability of gut microbiota in healthy adults. These findings suggest that a single dietary change involving high-fibre bread provides a practical way for adults to exceed recommended dietary fibre intake levels that improve gut microbiota composition and support gastrointestinal and metabolic health.

Cereals are one of the most important foods on which human beings rely to sustain basic life activities and are closely related to human health. This study investigated the effects of different steamed buns on intestinal microbiota. Three steamed buns were prepared using refined flour (RF), 1:1 mixed flour (MF), and whole wheat flour (WF). In vitro digestion simulations were conducted using a bionic gastrointestinal reactor (BGR) to examine their influence on intestinal microbiota. The results showed that at 0.5% addition, butyric acid and short-chain fatty acids in WF were significantly different from those in RF and MF (p < 0.05). WF also promoted the proliferation of beneficial microbiota, such as Megamonas and Subdoligranulum. At 0.5%, 1.0%, and 1.5% additions of WF, acetic acid and short-chain fatty acids at 1.5% WF increased by 1167.5% and 11.4% from 0.5% WF, respectively, and by 20.2% and 7.6% from 1.0% WF, respectively. WF also promoted the proliferation of Bifidobacterium, Lactobacillus, and Bacteroides and inhibited the growth of pathogenic microbiota, such as Streptococcus, Enterococcus, and Klebsiella. These findings support the consumption of whole cereals and offer insights into the development of new functional foods derived from wheat.

Constipation is common in children and can significantly affect quality of life. Prebiotics are reportedly helpful for constipation in adults, but few studies have examined their use in young children. In this study, the effect of 1-kestose (kestose), which has excellent bifidobacterial growth properties, on constipation in kindergarten children (n = 11) was compared with that of maltose (n = 12) in a randomized, double-blind study. Three grams of kestose per day for 8 weeks did not affect stool properties, but significantly increased the number of defecations per week (Median; 3 → 4 times/week, p = 0.017, effect size = 0.53). A significant decrease in Intestinibacter, a trend toward increased bifidobacteria, and a trend toward decreased Clostridium sensu stricto were observed after kestose ingestion, while concentrations of short-chain fatty acids in stools were unchanged.

MRI and PET are used in neuro-oncology for the detection and characterisation of lesions for malignancy to target surgical biopsy and to plan surgical resections or stereotactic radiosurgery. The critical role of short-chain fatty acids (SCFAs) in brain tumour biology has come to the forefront. The non-metabolised SCFA radiotracer, [18F]fluoropivalate (FPIA), shows low background signal in most tissues except eliminating organs and has appropriate human dosimetry. Tumour uptake of the radiotracer is, however, unknown. We investigated the uptake characteristics of FPIA in this pilot PET/MRI study.
Ten adult glioma subjects were identified based on radiological features using standard-of-care MRI prior to any surgical intervention, with subsequent histopathological confirmation of glioma subtype and grade (lower-grade - LGG - and higher-grade - HGG - patients). FPIA was injected as an intravenous bolus injection (range 342-368 MBq), and dynamic PET and MRI data were acquired simultaneously over 66 min.
All patients tolerated the PET/MRI protocol. Three patients were reclassified following resection and histology. Tumour maximum standardised uptake value (SUVmax,60) increased in the order LGG (WHO grade 2) < HGG (WHO grade 3) < HGG (WHO grade 4). The net irreversible solute transfer, Ki, and influx rate constant, K1, were significantly higher in HGG (p < 0.05). Of the MRI variables studied, DCE-MRI-derived extravascular-and-extracellular volume fraction (ve) was high in tumours of WHO grade 4 compared with other grades (p < 0.05). SLC25A20 protein expression was higher in HGG compared with LGG.
Tumoural FPIA PET uptake is higher in HGG compared to LGG. This study supports further investigation of FPIA PET/MRI for brain tumour imaging in a larger patient population.
Clinicaltrials.gov, NCT04097535.

Okara is a fiber-rich food by-product whereby biovalorization with Rhizopus oligosporus can improve its nutritional quality, generating fermentable substrates for improved gut health maintenance. This study evaluates the impact of okara- and biovalorized okara-containing biscuits consumption on gut health in Singapore adults.
Participants consume control (C), 20% flour-substituted okara (AOK), and 20% flour-substituted biovalorized okara (RO) biscuits for three weeks, with assessment of gut metabolites, microbiome, and dietary intake. Fecal valeric acid is significantly higher with RO compared to AOK (p = 0.005). RO and AOK have significantly higher total serum short-chain fatty acids (p = 0.002 and 0.018 respectively) and acetic acid (p = 0.007 and 0.030 respectively) compared to C. Higher serum propionic acid (p = 0.004) and lower fecal lithocholic acid (p = 0.009) are observed with RO. Although serum zonulin shows no significant difference amongst interventions, AOK reduces Clostridiales while RO increases Bifidobacterium.
Okara consumption improves serum SCFA regardless of fermentation while biovalorized okara further enhances gut metabolites by modulating gut microbiome.

Okara is a by-product of soymilk manufacturing and a rich source of protein and dietary fiber. This study investigates whether dietary soymilk-okara powder intake in the long term affects the body composition and gut microbiota flora in healthy Japanese adults. In total, 46 subjects (43 women) were enrolled. All subjects ingested 15 g of soymilk-okara powder every day for 12 weeks. Subjects\' body composition was assessed over four weeks. At baseline and after intervention for 12 weeks, fecal short-chain fatty acid concentrations and microbiota percentages were measured. The body muscle weight significantly increased, and the percentage of body fat significantly decreased at 4, 8, and 12 weeks after the intervention. The increase in body muscle after 12 weeks was 0.6 kg (interquartile range:-0.03 to 1.0). The decrease in body fat was -0.9% (interquartile range: -1.6 to -0.2). There was a significant negative correlation between the changes in body fat and body muscle. For the fecal percentages of Coriobacteriaceae, Lactobacillales, Bacteroides, Clostridium cluster IV, and Clostridium cluster XI, there were significant differences between the baseline and 12 weeks after the intervention. Furthermore, there were significant negative correlations between the changes in body fat percentage and fecal acetic acid and propionic acid levels. Therefore, a dietary intake of 15 g of soymilk-okara powder for 12 weeks induced a decrease in body fat, an increase in body muscle, and a change in fecal microbiota flora. Soymilk-okara powder is effective in improving body composition and changing the intestinal microbiota flora in healthy Japanese adults.

The oral and gut microbiomes have each been associated with food allergy status. Within food allergy, they may also influence reaction thresholds.
Our aim was to identify oral and gut microbiota associated with reaction thresholds in peanut allergy.
A total of 59 children aged 4 to 14 years with suspected peanut allergy underwent double-blind, placebo-controlled food challenge to peanut. Those children who reacted at the 300-mg or higher dose of peanut were classified as high-threshold (HT), those who reacted to lower doses were classified as low-threshold (LT), and those children who did not react were classified as not peanut allergic (NPA). Saliva and stool samples collected before challenge underwent DNA isolation followed by 16S rRNA sequencing and short-chain fatty acid measurement.
The 59 participants included 38 HT children and 13 LT children. Saliva microbiome α-diversity (Shannon index) was higher in LT children (P = .017). We identified saliva and stool microbiota that distinguished HT children from LT children, including oral Veillonella nakazawae (amplicon sequence variant 1979), which was more abundant in the HT group than in the LT group (false discovery rate [FDR] = 0.025), and gut Bacteroides thetaiotaomicron (amplicon sequence variant 6829), which was less abundant in HT children than in LT children (FDR = 0.039). Comparison with NPA children revealed consistent ordinal trends between these discriminating species and reaction thresholds. Importantly, many of these threshold-associated species were also correlated with short-chain fatty acid levels at the respective body sites, including between oral V nakazawae and oral butyrate (r = 0.57; FDR = 0.049).
Findings from this multiscale study raise the possibility of microbial therapeutics to increase reaction thresholds in children with food allergy.

OBJECTIVE: To study the influence of enteral feeding initiation time on intestinal flora and metabolites in very low birth weight (VLBW) infants.
METHODS: A total of 29 VLBW infants who were admitted to the Department of Neonatology, Children\'s Hospital of Chongqing Medical University, from June to December, 2020, were enrolled as subjects. According to the enteral feeding initiation time after birth, the infants were divided into two groups: <24 hours (n=15) and 24-72 hours (n=14). Fecal samples were collected at weeks 2 and 4 of hospitalization, and 16S rDNA high-throughput sequencing and gas chromatography-mass spectrometry were used to analyze the microflora and short-chain fatty acids (SCFAs) respectively in fecal samples.
RESULTS: The analysis of microflora showed that there was no significant difference between the two groups in Chao index (reflecting the abundance of microflora) and Shannon index (reflecting the diversity of microflora) at weeks 2 and 4 after birth (P>0.05). The analysis of flora composition showed that there was no significant difference in the main microflora at the phylum and genus levels between the two groups at weeks 2 and 4 after birth (P>0.05). The comparison of SCFAs between the two groups showed that the <24 hours group had a significantly higher level of propionic acid than the 24-72 hours group at week 4 (P<0.05), while there was no significant difference in the total amount of SCFAs and the content of the other SCFAs between the two groups (P>0.05).
CONCLUSIONS: Early enteral feeding has no influence on the diversity and abundance of intestinal flora in VLBW infants, but enteral feeding within 24 hours can increase the level of propionic acid, a metabolite of intestinal flora.
目的: 探讨不同肠内营养开始时间对极低出生体重儿肠道菌群及代谢产物的影响。方法: 选取2020年6~12月重庆医科大学附属儿童医院新生儿科收治的29例极低出生体重儿为研究对象，根据生后肠内营养开始时间（开奶时间）不同分为<24 h组（n=15）和24~72 h组（n=14）。采集患儿住院第2周和第4周的粪便标本，采用16S rDNA高通量测序和气相色谱-质谱法分别分析粪便样本的菌群和短链脂肪酸（short-chain fatty acids，SCFAs）。结果: 菌群结果显示，生后第2周和第4周2组间Chao指数（反映菌群丰富度）和Shannon指数（反映菌群多样性）差异无统计学意义（P>0.05）。菌群组成分析中，生后第2周和第4周2组间主要菌群在门、属水平上差异无统计学意义（P>0.05）。2组SCFAs比较显示，开奶时间<24 h组第4周丙酸高于24~72 h组（P<0.05），而2组SCFAs总量及其他各SCFAs含量差异无统计学意义（P>0.05）。结论: 较早开始肠内营养对极低出生体重儿肠道菌群多样性和丰富度无影响，但24 h内开始肠内营养可以使代谢产物丙酸水平增高。.

Undernutrition is associated with gut microbiota unbalance, and probiotics are believed to restore it and improve gut integrity. A randomized double-blind controlled trial was conducted to evaluate the efficacy of gummy L. plantarum Dad-13 (108-9 CFU/3 g) to prevent the progression of severe undernutrition. Two groups of moderate undernutrition infants were involved in this study, namely the placebo (n = 15) and probiotics (n = 15) groups, and were required to consume the product for 50 days. 16S rRNA sequencing and qPCR were used for gut microbiota analysis, and gas chromatography was used to analyze Short-Chain Fatty Acid (SCFA). The daily food intake of both groups was recorded using food records. Our results revealed that the probiotic group had better improvements regarding the anthropometry and nutritional status. In addition, L. plantarum Dad-13 modulated the butyric acid-producing bacteria to increase and inhibit the growth of Enterobacteriaceae. This gut modulation was associated with the increment in SCFA, especially total SCFA, propionic, and butyric acid. The number of L. plantarum was increased after the probiotic intervention. However, L. plantarum Dad-13 was not able to change the alpha and beta diversity. Therefore, L. plantarum Dad-13 has been proven to promote the growth of beneficial bacteria.

Resistant starch (RS) confers many health benefits, mostly through the microbial production of SCFAs, but foods containing appreciable RS are limited. High-amylose wheat (HAW) is high in RS and lowers the glycemic response of foods, but whether it can improve gastrointestinal health measures is unknown.
The objective of this study was to determine whether daily consumption of HAW food products improved markers of gastrointestinal health in healthy men and women compared with similar foods made from conventional wheat.
Eighty healthy adults (47 women and 33 men) were enrolled in a 4-arm parallel, randomized-controlled, double-blind trial. After a 2-wk low-dietary fiber run-in period, they were randomly allocated to 1 of 4 treatment groups: low-amylose wheat (LAW)-refined (LAW-R), LAW-wholemeal (LAW-W), HAW-refined (HAW-R), and HAW-wholemeal (HAW-W) and consumed the assigned test bread (160 g/d) and biscuits (75 g/d) for 4 wk. Fecal biochemical markers were measured at baseline and 4 wk. Microbial abundance and diversity were quantified using 16S ribosomal RNA sequencing and perceived gut comfort by a semiquantitative questionnaire completed at baseline, 2 wk, and 4 wk.
HAW showed similar effects on fecal output and excretion of total SCFA compared with LAW, but changes were observed in secondary measures for the refined treatment groups. At 4 wk, the HAW-R group had 38% higher fecal butyrate excretion than the LAW-R group (P < 0.05), and higher fecal SCFA-producing bacteria, Roseburia inulinivorans (P < 0.001), than at baseline. In comparison with baseline, LAW-R increased fecal p-cresol concentration, and fecal abundance of a p-cresol-producing bacterium, Clostridium from the Peptostreptococcaceae family, but both were reduced by HAW-R. Amylose level did not affect measures of fecal consistency or adversely affecting digestive comfort.
Increasing RS intake of healthy adults by substituting refined conventional wheat with refined HAW modulates fecal metabolites and microbes associated with gastrointestinal health.This trial was registered at anzctr.org.au as ACTRN12618001060235.