Constipation is a common gastrointestinal disorder that affects all age groups.Probiotics show efficacy in relieving constipation;however,their efficacy is highly strain-specific,and the genetic basis for this heterog...Constipation is a common gastrointestinal disorder that affects all age groups.Probiotics show efficacy in relieving constipation;however,their efficacy is highly strain-specific,and the genetic basis for this heteroge-neity remains unclear.This study investigated the genetic determinants and underlying mechanisms of different Bifidobacterium longum subsp.longum strains in alleviating constipation.Among the three strains evaluated in loperamide-induced constipation mice,only BZG4 significantly alleviated constipation.Comparative genomic analysis revealed that a unique xylooligosaccharide(XOS)utilization cluster was only located in the chromosome in strain BZG4,which was further validated by its ability to grow with XOS as the sole carbon source.Synbiotic supplementation with BZG4 and XOS produced synergistic effects,evidenced by significant improvements in fecal water content,5-h fecal pellet output,whole-gut transit time,and small intestinal propulsion rate.Mech-anistically,the synbiotic BZG4-XOS alleviated constipation by modulating gut microbiota to increase the butyric acid level in feces,thereby restoring the integrity of the enteric nervous system,regulating the relevant neu-romodulators and enhancing MUC2-dominated mucus and water secretion.These findings determined the strainspecific XOS cluster of BZG4 as a genetic basis for constipation relief and provided a genetic strategy for developing precision synbiotics targeting gastrointestinal motility disorders.展开更多
Arabinoxylan(AX),a prebiotic fiber known to improve the growth of Bifidobacterium longum subsp.longum,yet exhibits unclear regulatory mechanisms within the complex gut environment factors such as bile acids.This in vi...Arabinoxylan(AX),a prebiotic fiber known to improve the growth of Bifidobacterium longum subsp.longum,yet exhibits unclear regulatory mechanisms within the complex gut environment factors such as bile acids.This in vitro study aimed to investigate the interaction of AX and bile acids on the activity of Bifidobacterium longum subsp.longum.The results demonstrated that AX efficiently binds to bile acids,significantly enhancing the survival and metabolic activity of Bifidobacterium longum subsp.longum under bile acid stress.Specifically,AX-treated Bifidobacterium longum subsp.longum maintained acetate and lactate yields above 50%,outperforming both bile acid-only and glucose-treated conditions.The protective efficacy of AX was likely attributed to its elevated arabinose substitution levels and distinctive monosaccharide profile.These findings revealed AX as a microenvironment modulator that indirectly strengthens beneficial bacteria resilience via neutralizing bile acid toxicity.This study highlights the potential mechanism of dietary fiber to regulate gut microbes through bile acid modulation.展开更多
【目的】以新疆不同地域、不同人群来源的长双歧杆菌长亚种(Bifidobacterium longum subsp.longum)为研究对象,解析肠道专性共栖细菌在宿主人群中的系统发育和基因组多样性,为针对不同人群开发个性化功能益生菌提供理论依据。【方法】...【目的】以新疆不同地域、不同人群来源的长双歧杆菌长亚种(Bifidobacterium longum subsp.longum)为研究对象,解析肠道专性共栖细菌在宿主人群中的系统发育和基因组多样性,为针对不同人群开发个性化功能益生菌提供理论依据。【方法】从地理跨度较大的新疆喀什、伊犁的维吾尔族和哈萨克族母婴人群中分离出136株B.longum subsp.longum,并通过公共数据库整合来自国内其他地域人群的菌株进行比较基因组分析。【结果】B.longum subsp.longum基因组的平均大小、G+C含量、编码序列数量分别为2.38 Mb、59.91%、2160个。基于核心基因构建的系统发育树显示,来自新疆的所有菌株在系统发育树上属于4个进化支(clade),来自同一民族、不同地域人群的菌株其系统发育呈现不同的进化支,地理上更相近、不同人群来源的菌株存在一定程度的重叠。对更大地理范围(全中国)的分析显示,B.longum subsp.longum菌株呈现明显的东西部地理来源聚集特征和协同进化现象。基于附属基因和碳水化合物代谢功能基因的分析显示,来源于同一系统发育进化支的同一民族、不同地域人群菌株的功能基因谱丰度也差异较大;碳水化合物水解酶家族GH13(α-淀粉酶)和GH43(β-木糖苷酶)等在喀什地区菌株基因组中更为丰富;相反,地理上相近、即使来自不同民族人群的菌株,其基因组中蛋白质直系同源簇(cluster of orthologous groups of proteins,COG)功能基因谱、碳水化合物水解酶关联基因家族谱更相似。【结论】新疆不同地域人群来源的B.longum subsp.longum菌株系统发育呈现明显的地理和民族分布特征以及功能基因分布特征,地理尺度范围越大,菌株的地理分布特征越明显。需要基于更大范围菌株基因组的大数据进一步验证人群的地理分布尺度与菌株协同进化和特异性的关系。展开更多
基金supported by the National Key R&D Pro-gram of China(No.2022YFF1100100)Cross-Innovation Open Project of Food Flavor and Health,Beijing Technology&Business Uni-versity(No.FFHCI-2025010).
文摘Constipation is a common gastrointestinal disorder that affects all age groups.Probiotics show efficacy in relieving constipation;however,their efficacy is highly strain-specific,and the genetic basis for this heteroge-neity remains unclear.This study investigated the genetic determinants and underlying mechanisms of different Bifidobacterium longum subsp.longum strains in alleviating constipation.Among the three strains evaluated in loperamide-induced constipation mice,only BZG4 significantly alleviated constipation.Comparative genomic analysis revealed that a unique xylooligosaccharide(XOS)utilization cluster was only located in the chromosome in strain BZG4,which was further validated by its ability to grow with XOS as the sole carbon source.Synbiotic supplementation with BZG4 and XOS produced synergistic effects,evidenced by significant improvements in fecal water content,5-h fecal pellet output,whole-gut transit time,and small intestinal propulsion rate.Mech-anistically,the synbiotic BZG4-XOS alleviated constipation by modulating gut microbiota to increase the butyric acid level in feces,thereby restoring the integrity of the enteric nervous system,regulating the relevant neu-romodulators and enhancing MUC2-dominated mucus and water secretion.These findings determined the strainspecific XOS cluster of BZG4 as a genetic basis for constipation relief and provided a genetic strategy for developing precision synbiotics targeting gastrointestinal motility disorders.
基金supported by the National Natural Science Foundation of China[No.32202068]the Natural Science Foundation of Fujian Province[No.2022J01332].
文摘Arabinoxylan(AX),a prebiotic fiber known to improve the growth of Bifidobacterium longum subsp.longum,yet exhibits unclear regulatory mechanisms within the complex gut environment factors such as bile acids.This in vitro study aimed to investigate the interaction of AX and bile acids on the activity of Bifidobacterium longum subsp.longum.The results demonstrated that AX efficiently binds to bile acids,significantly enhancing the survival and metabolic activity of Bifidobacterium longum subsp.longum under bile acid stress.Specifically,AX-treated Bifidobacterium longum subsp.longum maintained acetate and lactate yields above 50%,outperforming both bile acid-only and glucose-treated conditions.The protective efficacy of AX was likely attributed to its elevated arabinose substitution levels and distinctive monosaccharide profile.These findings revealed AX as a microenvironment modulator that indirectly strengthens beneficial bacteria resilience via neutralizing bile acid toxicity.This study highlights the potential mechanism of dietary fiber to regulate gut microbes through bile acid modulation.
文摘【目的】以新疆不同地域、不同人群来源的长双歧杆菌长亚种(Bifidobacterium longum subsp.longum)为研究对象,解析肠道专性共栖细菌在宿主人群中的系统发育和基因组多样性,为针对不同人群开发个性化功能益生菌提供理论依据。【方法】从地理跨度较大的新疆喀什、伊犁的维吾尔族和哈萨克族母婴人群中分离出136株B.longum subsp.longum,并通过公共数据库整合来自国内其他地域人群的菌株进行比较基因组分析。【结果】B.longum subsp.longum基因组的平均大小、G+C含量、编码序列数量分别为2.38 Mb、59.91%、2160个。基于核心基因构建的系统发育树显示,来自新疆的所有菌株在系统发育树上属于4个进化支(clade),来自同一民族、不同地域人群的菌株其系统发育呈现不同的进化支,地理上更相近、不同人群来源的菌株存在一定程度的重叠。对更大地理范围(全中国)的分析显示,B.longum subsp.longum菌株呈现明显的东西部地理来源聚集特征和协同进化现象。基于附属基因和碳水化合物代谢功能基因的分析显示,来源于同一系统发育进化支的同一民族、不同地域人群菌株的功能基因谱丰度也差异较大;碳水化合物水解酶家族GH13(α-淀粉酶)和GH43(β-木糖苷酶)等在喀什地区菌株基因组中更为丰富;相反,地理上相近、即使来自不同民族人群的菌株,其基因组中蛋白质直系同源簇(cluster of orthologous groups of proteins,COG)功能基因谱、碳水化合物水解酶关联基因家族谱更相似。【结论】新疆不同地域人群来源的B.longum subsp.longum菌株系统发育呈现明显的地理和民族分布特征以及功能基因分布特征,地理尺度范围越大,菌株的地理分布特征越明显。需要基于更大范围菌株基因组的大数据进一步验证人群的地理分布尺度与菌株协同进化和特异性的关系。
