Ask: I used to ride my bike 100 miles a week, but last year I started having a problem with my knee. I could walk all day, but the moment I got up to walk uphill, my left knee gave out.
I gave up cycling to run and easily do three 5K runs a week, but I can’t climb a flight of stairs. If my leg goes beyond a certain “degree” of curvature, it gives way.
Stuart A, via email.
Answer: Your letter reminds me of a patient whose knee stuck at specific times, very similar to yours. He could play squash, but he discovered that it suddenly caused him to collapse from pain on the court. He could climb a ladder, but his knee would get stuck when going up the stairs.
I sent him to an orthopedic specialist, who ordered an MRI, which revealed a loose fragment of cartilage that got stuck in the hinge of his knee joint.
I used to ride my bike 100 miles a week, but last year I started having a problem with my knee. I could walk all day, but the moment I got up to walk uphill, my left knee gave way (file photo)
I’m wondering if you might also have some sort of loose fragment in your knee and suggest you ask your GP to refer you for an MRI. Any of these fragments can be removed through minimally invasive surgery. Then you should be able to get back to doing all the activities you enjoy.
Ask: I have suffered from bloating, intestinal bloating and chronic constipation for years. A recent lactulose breath test showed he had very low levels of hydrogen but an elevated level of methane. They have sent me to a dietitian. Is there anything I can do to address this level of methane in my gut? I am 66 years old.
Colin Miller, Chester
Answer: The hydrogen and methane breath test is a non-invasive way to diagnose common gastrointestinal problems, such as bacterial overgrowth or food intolerance. As you may know, the test involves fasting for 12 hours before swallowing lactulose, a type of sugar, and then studying the levels of two gases (hydrogen and methane) produced by gut microbes in the air you exhale.
Microbes produce gases as they break down the food we eat. High hydrogen levels usually indicate intolerance to some sugars, such as milk sugar (lactose) and fructose (fruit sugar). As a result, more of them remain in the large intestine so that the bacteria can act.
Elevated hydrogen levels can also be a sign of small intestine bacterial overgrowth (SIBO), which means that there are more bacteria than there should be in the small intestine (they are mainly found in the large intestine).
The more bacteria there are, the more gas they produce. However, we can rule out both causes in your case given your low hydrogen readings.
But its excessive methane level is evidence of an increase in certain types of organisms in the large intestine (including methanobrevibactersmithii) that feed on “fermentable” carbohydrates, such as lactose or fructose. It is these that cause bloating, pain and constipation.
This, along with other symptoms, suggests that you have a variant of irritable bowel syndrome associated with constipation: research has confirmed a significant link between the severity of constipation and elevated methane levels. (The opposite occurs in patients with irritable bowel syndrome with diarrhea).
The usual treatment is a combination of antibiotics; prebiotics (which nourish beneficial bacteria); and probiotics (to increase levels of good bacteria in the gut). However, antibiotic treatment is not the best approach, as methane-producing organisms are often resistant to most antibiotics.
I have suffered from bloating, intestinal distention and chronic constipation for years (file photo)
Although some patients are prescribed antibiotics rifaximin and neomycin, these can disrupt other valuable parts of the microbiome. Dietary changes are the best way to get prebiotics and probiotics (i.e. increasing your consumption of vegetables and fruits) and this is why you have been referred to a dietitian, who will be best placed to offer advice.
It is a treatment that can last months. But it should gradually improve your microbiome, resulting in the resolution of many of your symptoms, so give it time.
Write to Dr Scurr at Good Health, Daily Mail, 9 Derry Street, London, W8 5HY or email drmartin@dailymail.co.uk. Dr. Scurr cannot correspond personally. Answers should be taken in a general context. Consult your family doctor if you have any health problem.
