14.One of the most important recent medical breakthroughs has been the impact of gut flora(腸道菌群)on overall health.This dynamic mix of bacteria in the digestive tract(消化道)may affect everything from obesity to asthma(哮喘).
The Gut-Mood Link
Anyone who's ever experienced"butterflies"in his or her stomach knows that the gut and the brain are connected.But until recently,scientists hadn't realized that the trillions of bacteria in our digestive tract may be driving the relationship.
One recent experiment suggests that you can control calm.Canadian researchers gave healthy mice a mixture of antibiotics,which change the makeup of GI-tract(胃腸道)bacteria.Over two weeks,some animals became more anxious and some less,depending on which drugs they received.
In another study,when gut bacteria from calm mice were transferred to anxious mice,the jittery(緊張的)creatures seemed less nervous.
UCLA professor Kirsten Tillisch,doctor of medicine,recently had healthy women eat a yogurt rich in certain types of"good"probiotic(益生菌的)bacteria.Two'Control groups ate yogurt without such bacteria or ate nothing.Brain scans of the probiotic-yogurt eaters indicated changes in regions that could be associated with a less-anxious response in fearful or stressful situations compared with the control groups.
Scientists are even exploring whether gut microbes(微生物)might treat some brain disorders.
A new study in Cell found that mice with features of autism(自ICJ癥)given a type of bacteria in healthy human GI tracts exhibited less autism-like behavior.In a recent case report,a Boston ps} chiatrist says a course of certain probiotics and antibiotics helped relieve a patient's compulsive disorder.
-We tend to focus on how your mood affects your body from the top down,not the bottom up,"says Dr.Tillisch."Now we know that the gut affects how your brain responds to the environment-it's a remarkable change in thinking."
How Bacteria Talk to the Brain
Scientists aren't sure how gut flora affect brain chemistry.One theory is that the bacteria access pathways along the nerve,the main highway in the nervous system that links the brain to the gut.
Another is that the bacteria influence the immune system,releasing chemicals that affect conditions like depression.Finally,researchers believe that bacteria produce or affect the metabolism(新陳代'i) of chemicals,which change brain function.
Dr.Tillisch told me that patients always ask which probiotics will lift their mood.Her answer:
"We don't know yet,but we hope to one day."In the future,patients might receive probiotics or transplant(移植) in which bacteria from the gut of a healthy person are transferred to the gut of a sic':one-to prevent or treat mental health issues.But these approaches are years away from primary time.Until then,a diet rich in fruit and veggies helps cultivate(培養(yǎng))better-balanced microbes than a typical Western diet high in animal and processed products.Avoiding unnecessary antibiotics,particularly in early childhood,may also establish healthier gut bacteria.
63.According to the passage,gut bacteria might help us in many ways EXCEPTD.
A.lightening our mood
B.treating autism
C.relieving depression
D.transplanting gut flora
64.The missing sentence"Everyday foods may also affect the composition of gut bacteria,and in turn,brain chemistry."could be put beforeC•
A.Paragraph 2 B.Paragraph 3 C.Paragraph 4 D.Paragraph 5
65.Which of the following can be the best subtitle for the last paragraph?A
A.Cultivating a Happier Gut B.Growing Bacteria in the Future
C.Balancing Microbes and Diet D.Living a Happy Healthy Life.
分析 本文屬于說明文閱讀,作者通過這篇文章向我們介紹了腸道菌可以幫助改善我們的情緒,減輕壓力,并且對我們的健康有益,同時介紹了應(yīng)該如何培養(yǎng)健康 的腸道菌群.
解答 63.D 細(xì)節(jié)拉筋題:根據(jù)文章的二三四段In another study,when gut bacteria from calm mice were transferred to anxious mice,the jittery(緊張的)creatures seemed less nervous.可知腸道菌群可以改善我們的情緒,減輕壓力;第五段A new study in Cell found that mice with features of autism 可知腸道菌群可以治療自閉癥,而D選項在文中沒有提及,故選D.
64.C 推理判斷題:根據(jù)第三段scientists hadn't realized that the trillions of bacteria in our digestive tract may be driving the relationship.可知接下來要介紹的是食物和腸道以及大腦化學(xué)物質(zhì)的關(guān)系,因此這句話應(yīng)該放在第四段之前,故選C.
65.A 段落大意題:根據(jù)最后一段的內(nèi)容:a diet rich in fruit and veggies helps cultivate(培養(yǎng))better-balanced microbes than a typical Western diet high in animal and processed products.可知本段向我們介紹的是應(yīng)該如何培養(yǎng)更健康的腸道菌群,故選A.
點評 考查學(xué)生的細(xì)節(jié)理解和推理判斷能力.做細(xì)節(jié)理解題時一定要找到文章中的原句,和題干進(jìn)行比較,再做出正確選擇.在做推理判斷題時不要以個人的主觀想象代替文章的事實,要根據(jù)文章事實進(jìn)行合乎邏輯的推理判斷.