日本京都大學(xué)等機(jī)構(gòu)研究人員日前聯(lián)合發(fā)表報(bào)告說(shuō),，定期給實(shí)驗(yàn)鼠喂食雙歧桿菌,，可使實(shí)驗(yàn)鼠比同類更長(zhǎng)壽。
研究人員選取20只10個(gè)月大的實(shí)驗(yàn)鼠,，每周3次給它們喂食雙歧桿菌“LKM512”，每只實(shí)驗(yàn)鼠每次食用雙歧桿菌約2000萬(wàn)個(gè)，相當(dāng)于市場(chǎng)銷售的酸奶150毫升所含菌量,。而給對(duì)照組的實(shí)驗(yàn)鼠每次只進(jìn)食生理鹽水,。
10個(gè)月大的實(shí)驗(yàn)鼠相當(dāng)于人類30歲至34歲的年紀(jì)。喂食雙歧桿菌一直持續(xù)到實(shí)驗(yàn)鼠相當(dāng)于人類約70歲的時(shí)候,。這時(shí)這些實(shí)驗(yàn)鼠的生存率達(dá)約80%,，而對(duì)照組實(shí)驗(yàn)鼠的生存率只有約30%，差異明顯,。另外,，定期被喂食雙歧桿菌的實(shí)驗(yàn)鼠毛非常整齊，外觀顯得年輕,。
另外,，僅飲用生理鹽水的實(shí)驗(yàn)鼠約有20%出現(xiàn)腫瘤或潰瘍等疾病，而食用雙歧桿菌的實(shí)驗(yàn)鼠則基本沒(méi)有患這些病,。
研究人員認(rèn)為,，攝入雙歧桿菌使實(shí)驗(yàn)鼠腸道內(nèi)多聚胺的量增加，有效抑制了腸道老化,，并起到了抗炎癥的作用,。
研究人員表示，不光是“LKM512”,，其他品種的雙歧桿菌應(yīng)該能產(chǎn)生同樣的功效,。
本項(xiàng)研究的相關(guān)成果已在新一期美國(guó)在線科學(xué)雜志《科學(xué)公共圖書館—綜合卷》上發(fā)表。(生物谷 Bioon.com)
doi:10.1371/journal.pone.0023652
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Longevity in Mice Is Promoted by Probiotic-Induced Suppression of Colonic Senescence Dependent on Upregulation of Gut Bacterial Polyamine Production
Mitsuharu Matsumoto, Shin Kurihara, Ryoko Kibe, Hisashi Ashida, Yoshimi Benno2
Background Chronic low-grade inflammation is recognized as an important factor contributing to senescence and age-related diseases. In mammals, levels of polyamines (PAs) decrease during the ageing process; PAs are known to decrease systemic inflammation by inhibiting inflammatory cytokine synthesis in macrophages. Reductions in intestinal luminal PAs levels have been associated with intestinal barrier dysfunction. The probiotic strain Bifidobacterium animalis subsp. lactis LKM512 is known to increase intestinal luminal PA concentrations. Methodology/Principal Findings We supplemented the diet of 10-month-old Crj:CD-1 female mice with LKM512 for 11 months, while the controls received no supplementation. Survival rates were compared using Kaplan–Meier survival curves. LKM512-treated mice survived significantly longer than controls (P<0.001); moreover, skin ulcers and tumors were more common in the control mice. We then analyzed inflammatory and intestinal conditions by measuring several markers using HPLC, ELISA, reverse transcription-quantitative PCR, and histological slices. LKM512 mice showed altered 16S rRNA gene expression of several predominant intestinal bacterial groups. The fecal concentrations of PAs, but not of short-chain fatty acids, were significantly higher in LKM512-treated mice (P<0.05). Colonic mucosal function was also better in LKM512 mice, with increased mucus secretion and better maintenance of tight junctions. Changes in gene expression levels were evaluated using the NimbleGen mouse DNA microarray. LKM512 administration also downregulated the expression of ageing-associated and inflammation-associated genes and gene expression levels in 21-month-old LKM512-treated mice resembled those in 10-month-old untreated (younger) mice. Conclusion/Significance Our study demonstrated increased longevity in mice following probiotic treatment with LKM512, possibly due to the suppression of chronic low-grade inflammation in the colon induced by higher PA levels. This indicates that ingestion of specific probiotics may be an easy approach for improving intestinal health and increasing lifespan. Further studies are required to clarify its effectiveness in humans.
