{"id":31802,"date":"2025-10-29T17:20:26","date_gmt":"2025-10-29T08:20:26","guid":{"rendered":"https:\/\/sonomono.jp\/?p=31802"},"modified":"2026-08-03T17:17:28","modified_gmt":"2026-08-03T08:17:28","slug":"natto-hakase-40","status":"publish","type":"post","link":"https:\/\/sonomono.jp\/en\/natto-hakase\/natto-hakase-40\/","title":{"rendered":"Gut Flora in Infants: When Is It Established and Why Early Care Matters"},"content":{"rendered":"<div class=\"p-blogParts post_content\" data-partsID=\"18259\">\n<figure class=\"wp-block-image size-full pc_only u-mb-ctrl u-mb-20 is-style-border\"><a href=\"https:\/\/sonomono.jp\/shopping\/natto\/\"><img src=\"https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/11\/bnr_natto1-e1670976774413.png\" alt=\"\u751f\u304d\u3066\u8178\u307e\u3067\u5c4a\u304f \u7d0d\u8c46\u83cc\u3092\u6bce\u65e5\u624b\u8efd\u306b\u3002\u305d\u306e\u3082\u306e\u7d0d\u8c46\" class=\"wp-image-18216\"\/><\/a><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full sp_only u-mb-ctrl u-mb-20 is-style-border\"><a href=\"https:\/\/sonomono.jp\/shopping\/natto\/\"><img src=\"https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/11\/bnr_natto2_sp-e1670976733638.png\" alt=\"\u751f\u304d\u3066\u8178\u307e\u3067\u5c4a\u304f \u7d0d\u8c46\u83cc\u3092\u6bce\u65e5\u624b\u8efd\u306b\u3002\u305d\u306e\u3082\u306e\u7d0d\u8c46\" class=\"wp-image-18313\"\/><\/a><\/figure>\n<\/div>\n\n\n\n<h2 class=\"wp-block-heading is-style-default u-mb-ctrl u-mb-10 has-swl-main-color has-swl-pale-02-background-color has-text-color has-background\">After the weaning period, an infant&#8217;s gut microbiome reaches the same diversity as an adult&#8217;s.<\/h2>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" loading=\"lazy\" width=\"1000\" height=\"683\" src=\"https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/10\/rinyushoku-2.jpg\" alt=\"\" class=\"wp-image-18011\" srcset=\"https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/10\/rinyushoku-2.jpg 1000w, https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/10\/rinyushoku-2-382x261.jpg 382w, https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/10\/rinyushoku-2-150x102.jpg 150w, https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/10\/rinyushoku-2-768x525.jpg 768w\" sizes=\"(max-width: 1000px) 100vw, 1000px\" \/><\/figure>\n\n\n\n<p><strong>When is gut flora established?<\/strong> By the end of the weaning period, a child\u2019s intestinal microbiome reaches diversity comparable to adults.<\/p>\n\n\n\n<p>While in the womb, a fetus\u2019s gut is considered <strong>sterile<\/strong>. In contrast, the adult gut contains roughly <strong>1,000 different bacterial species<\/strong>, totaling <strong>100 trillion to 1,000 trillion bacteria<\/strong>. This symbiotic relationship with gut bacteria begins <strong>at birth<\/strong>.<\/p>\n\n\n\n<ul>\n<li>In the <strong>first 1\u20132 days after birth<\/strong>, newborn stool contains almost no bacteria.<\/li>\n\n\n\n<li>Within <strong>24 hours<\/strong>, <strong>Escherichia coli<\/strong> and <strong>Staphylococcus<\/strong> (potentially harmful bacteria), along with <strong>Enterococcus<\/strong> and <strong>Clostridium<\/strong> (neutral or beneficial bacteria), start to proliferate.<\/li>\n\n\n\n<li>By <strong>day 3\u20134<\/strong>, <strong>lactic acid bacteria<\/strong> and <strong>Bifidobacteria<\/strong> (beneficial bacteria) begin to increase.<\/li>\n<\/ul>\n\n\n\n<p>After these initial stages, a variety of bacteria start colonizing the gut. By around <strong>6 months of age<\/strong>, after the weaning period, the infant\u2019s gut microbiota reaches a <strong>stable phase<\/strong>, showing <strong>adult-like diversity<\/strong> in bacterial composition.<\/p>\n\n\n\n<p>However, studies show that <strong>feeding patterns<\/strong>\u2014whether breastfeeding, formula, or solid foods\u2014can significantly influence the gut microbiome during the <strong>first 2\u20133 years of life<\/strong>. From <strong>childhood through adolescence (ages 4\u201317)<\/strong>, bacterial diversity continues to increase, eventually developing <strong>sex-specific microbial patterns<\/strong>.<\/p>\n\n\n\n<p>In summary, <strong>gut bacteria are initially transferred from the mother<\/strong> and acquired from the surrounding environment, starting a symbiotic relationship. After a period of instability in infancy, the gut microbiome <strong>stabilizes during early childhood<\/strong> and <strong>matures through childhood into adolescence<\/strong>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading is-style-default u-mb-ctrl u-mb-10 has-swl-main-color has-swl-pale-02-background-color has-text-color has-background\">How Birth Method and Feeding Patterns Affect Gut Microbiome Diversity<\/h2>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" loading=\"lazy\" width=\"1000\" height=\"667\" src=\"https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/10\/junyu.jpg\" alt=\"\" class=\"wp-image-18009\" srcset=\"https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/10\/junyu.jpg 1000w, https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/10\/junyu-382x255.jpg 382w, https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/10\/junyu-150x100.jpg 150w, https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/10\/junyu-768x512.jpg 768w\" sizes=\"(max-width: 1000px) 100vw, 1000px\" \/><\/figure>\n\n\n\n<p>Research suggests that the relationship between humans and bacteria may begin <strong>even before birth<\/strong>, as bacteria have been detected in the <strong>placenta and umbilical cord<\/strong>, potentially influencing the composition of the infant gut microbiome.<\/p>\n\n\n\n<p>The <strong>mode of delivery<\/strong> at birth has a direct impact on gut microbiome diversity. Studies report that <strong>infants born vaginally<\/strong> tend to have a more <strong>diverse and healthy bacterial community<\/strong> compared to those born via <strong>cesarean section<\/strong>.<\/p>\n\n\n\n<p>Additionally, <strong>feeding patterns<\/strong>, whether breastfeeding, formula feeding, or introducing solid foods, can significantly alter the diversity of the gut microbiota.<\/p>\n\n\n\n<p>One study highlights the role of <strong>human milk oligosaccharides (HMOs)<\/strong> found in breast milk:<\/p>\n\n\n\n<ul>\n<li><strong>Colostrum:<\/strong> ~2% concentration of HMOs<\/li>\n\n\n\n<li><strong>Mature milk:<\/strong> ~1% concentration of HMOs<\/li>\n<\/ul>\n\n\n\n<p>HMOs selectively promote the growth of <strong>Bifidobacteria<\/strong>, beneficial bacteria that support a healthy gut environment in infants.<\/p>\n\n\n\n<h2 class=\"wp-block-heading is-style-default u-mb-ctrl u-mb-10 has-swl-main-color has-swl-pale-02-background-color has-text-color has-background\">Supporting Gut Health from the Weaning Stage Leads to Lifelong Wellness<\/h2>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" loading=\"lazy\" width=\"1000\" height=\"751\" src=\"https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/10\/freeze_babyfood.jpg\" alt=\"\" class=\"wp-image-18010\" srcset=\"https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/10\/freeze_babyfood.jpg 1000w, https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/10\/freeze_babyfood-382x287.jpg 382w, https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/10\/freeze_babyfood-150x113.jpg 150w, https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/10\/freeze_babyfood-768x577.jpg 768w\" sizes=\"(max-width: 1000px) 100vw, 1000px\" \/><\/figure>\n\n\n\n<p>During <strong>infancy and early childhood (0\u20133 years)<\/strong>, the gut microbiome is highly dynamic. It is therefore important to support gut health by providing <strong>beneficial bacteria<\/strong> such as <strong>lactic acid bacteria, Bifidobacteria, and Bacillus subtilis (found in natto)<\/strong>, along with <strong>dietary fiber<\/strong>, especially <strong>soluble fiber<\/strong>, through <strong>fermented foods<\/strong>.<\/p>\n\n\n\n<p>Maintaining a healthy gut during this period can contribute to:<\/p>\n\n\n\n<ul>\n<li><strong>Proper growth and development<\/strong><\/li>\n\n\n\n<li><strong>Reduced risk of allergies<\/strong><\/li>\n\n\n\n<li><strong>Stronger immune function<\/strong><\/li>\n\n\n\n<li><strong>Overall long-term health<\/strong><\/li>\n<\/ul>\n\n\n\n<p>This is particularly important for <strong>infants born via cesarean section<\/strong> or those primarily fed <strong>formula<\/strong>, as careful attention to gut-friendly foods during weaning can help them enjoy <strong>a healthier early childhood<\/strong>.<\/p>\n\n\n\n<p>Even in adults, <strong>gut microbiome diversity and balance<\/strong> are critical for maintaining health. However, establishing a healthy gut during infancy is especially vital because it can <strong>influence growth, immune development, and long-term wellness<\/strong>.<\/p>\n\n\n\n<p>Supporting gut health helps regulate <strong>digestion, nutrient absorption, and metabolism of foods and medications<\/strong>, and contributes to <strong>overall physical and mental well-being<\/strong>. By managing daily diet and stress, and by actively including <strong>fermented foods and dietary fiber<\/strong>, parents can help their children maintain <strong>healthy digestion and enjoy a happy, vibrant early childhood<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Final Thoughts: Supporting Your Child\u2019s Gut Health Safely<\/h3>\n\n\n\n<p>Establishing a healthy gut microbiome from <strong>birth through early childhood<\/strong> is a crucial step in supporting your child\u2019s <strong>growth, immune function, and long-term health<\/strong>. Introducing <strong>fermented foods<\/strong> like natto, along with <strong>dietary fiber and probiotics<\/strong>, can help promote a balanced gut environment during the <strong>dynamic weaning period<\/strong>.<\/p>\n\n\n\n<p><strong><span class=\"swl-marker mark_yellow\">Important not<\/span>e:<\/strong> This article is intended for <strong>informational purposes only<\/strong> and does <strong>not constitute medical advice<\/strong>. Always consult a <strong>pediatrician or qualified healthcare professional<\/strong> before making significant changes to your child\u2019s diet, particularly when introducing fermented foods, supplements, or probiotics. Individual sensitivities, allergies, or health conditions may affect your child\u2019s suitability for specific foods.<\/p>\n\n\n\n<p>By following safe preparation methods, observing your child\u2019s tolerance, and providing a balanced diet, you can help foster a <strong>healthy gut environment<\/strong> that may benefit <strong>digestive health, immunity, and overall well-being<\/strong> well into adulthood.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote\">\n<p>References\/Websites (Japanese)<\/p>\n<cite>1) What is the Intestinal Microbiota (Intestinal Flora)? Health and Longevity Network: Foundation for Longevity Science<br><a href=\"https:\/\/www.tyojyu.or.jp\/net\/kenkou-tyoju\/kenko-cho\/chonai-saikin.html\">https:\/\/www.tyojyu.or.jp\/net\/kenkou-tyoju\/kenko-cho\/chonai-saikin.html<\/a><br>2) Shigeki Baba, Masaya Sasaki, Akira Ando: Intestinal Microbiota and Dysbiosis, Journal of the Japanese Society for Parenteral and Enteral Nutrition, 33 (5), 1099-1104, 2018<br>3) Kentaro Shimizu et al.: Intestinal Microbiota, Changes in the Intestinal Environment, and the Efficacy of Synbiotic Therapy in SIRS Patients, Journal of the Japanese Society of Emergency Medicine, 17, 833-44, 2006<br>4) Chihaya Yamada: Metabolic Functions of Anaerobic Bacteria Living in the Intestines of Humans and Animals: From the Metabolic Functions of Bifidobacteria and Methanogens to Applied Research, Chemistry and Biology, 60 (9), 446-452, 2022<br><br><strong>References\/Websites (English)<\/strong><br>5) Hui Li, Junjun Ni and Hong Qing\uff1aGut Microbiota: Critical Controller and Intervention Targett in Brain Aging and Cognitive Impairment. <em>Front. Aging Neurosci.<\/em>, 25 June 2021, Sec. Nurocognitive Aging and Behavior, <br><a href=\"http:\/\/doi.org\/10.3389\/fnagi.2021.671142\">http:\/\/doi.org\/10.3389\/fnagi.2021.671142<\/a><\/cite><\/blockquote>\n\n\n<div class=\"p-blogParts post_content\" data-partsID=\"18259\">\n<figure class=\"wp-block-image size-full pc_only u-mb-ctrl u-mb-20 is-style-border\"><a href=\"https:\/\/sonomono.jp\/shopping\/natto\/\"><img src=\"https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/11\/bnr_natto1-e1670976774413.png\" alt=\"\u751f\u304d\u3066\u8178\u307e\u3067\u5c4a\u304f \u7d0d\u8c46\u83cc\u3092\u6bce\u65e5\u624b\u8efd\u306b\u3002\u305d\u306e\u3082\u306e\u7d0d\u8c46\" class=\"wp-image-18216\"\/><\/a><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full sp_only u-mb-ctrl u-mb-20 is-style-border\"><a href=\"https:\/\/sonomono.jp\/shopping\/natto\/\"><img src=\"https:\/\/sonomono.jp\/wp-content\/uploads\/2022\/11\/bnr_natto2_sp-e1670976733638.png\" alt=\"\u751f\u304d\u3066\u8178\u307e\u3067\u5c4a\u304f \u7d0d\u8c46\u83cc\u3092\u6bce\u65e5\u624b\u8efd\u306b\u3002\u305d\u306e\u3082\u306e\u7d0d\u8c46\" class=\"wp-image-18313\"\/><\/a><\/figure>\n<\/div>\n\n\n\n\n","protected":false},"excerpt":{"rendered":"<p>Learn how to support your baby\u2019s gut health from birth through early childhood. Discover the role of probiotics, fermented foods, and dietary fiber in establishing a balanced gut microbiome, promoting immunity, digestion, and long-term wellness.<\/p>\n","protected":false},"author":10,"featured_media":18011,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"swell_btn_cv_data":"","footnotes":"","_locale":"en_US","_original_post":"https:\/\/sonomono.jp\/?p=17983","_wp_rev_ctl_limit":""},"categories":[58,140],"tags":[270,261,201],"_links":{"self":[{"href":"https:\/\/sonomono.jp\/wp-json\/wp\/v2\/posts\/31802"}],"collection":[{"href":"https:\/\/sonomono.jp\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sonomono.jp\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sonomono.jp\/wp-json\/wp\/v2\/users\/10"}],"replies":[{"embeddable":true,"href":"https:\/\/sonomono.jp\/wp-json\/wp\/v2\/comments?post=31802"}],"version-history":[{"count":2,"href":"https:\/\/sonomono.jp\/wp-json\/wp\/v2\/posts\/31802\/revisions"}],"predecessor-version":[{"id":31804,"href":"https:\/\/sonomono.jp\/wp-json\/wp\/v2\/posts\/31802\/revisions\/31804"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/sonomono.jp\/wp-json\/wp\/v2\/media\/18011"}],"wp:attachment":[{"href":"https:\/\/sonomono.jp\/wp-json\/wp\/v2\/media?parent=31802"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sonomono.jp\/wp-json\/wp\/v2\/categories?post=31802"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sonomono.jp\/wp-json\/wp\/v2\/tags?post=31802"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}